diff --git a/propositions/migrations/0005_remove_nb_yes_no_fields.py b/propositions/migrations/0005_remove_nb_yes_no_fields.py
new file mode 100644
index 0000000..4f09c1e
--- /dev/null
+++ b/propositions/migrations/0005_remove_nb_yes_no_fields.py
@@ -0,0 +1,24 @@
+# Generated by Django 2.2.9 on 2020-01-05 15:26
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("propositions", "0004_prop_renaming_and_cleaning"),
+    ]
+
+    operations = [
+        migrations.RemoveField(model_name="proposition", name="nb_no",),
+        migrations.RemoveField(model_name="proposition", name="nb_yes",),
+        migrations.AlterField(
+            model_name="answer",
+            name="proposition",
+            field=models.ForeignKey(
+                on_delete=django.db.models.deletion.CASCADE,
+                to="propositions.Proposition",
+            ),
+        ),
+    ]
diff --git a/propositions/models.py b/propositions/models.py
index 7f4eda0..0ff1f74 100644
--- a/propositions/models.py
+++ b/propositions/models.py
@@ -12,8 +12,6 @@ class Proposition(models.Model):
         ErnestoUser, on_delete=models.CASCADE, verbose_name="Proposé par"
     )
     link = models.URLField(blank=True)
-    nb_yes = models.IntegerField(default=0, verbose_name="nombre de réponses oui")
-    nb_no = models.IntegerField(default=0, verbose_name="nombre de réponses non")
 
     def __str__(self):
         return self.name
@@ -27,10 +25,7 @@ class Answer(models.Model):
     YES = "oui"
     NO = "non"
 
-    REP_CHOICES = [
-        (YES, "Oui"),
-        (NO, "Non")
-    ]
+    REP_CHOICES = [(YES, "Oui"), (NO, "Non")]
 
     proposition = models.ForeignKey(Proposition, on_delete=models.CASCADE)
     user = models.ForeignKey(User, on_delete=models.CASCADE)
diff --git a/propositions/tests.py b/propositions/tests.py
index e78a053..1d53b69 100644
--- a/propositions/tests.py
+++ b/propositions/tests.py
@@ -44,8 +44,6 @@ class PropositionCreateTest(TestCase):
         self.assertEqual(proposition.artist, "bar")
         self.assertEqual(proposition.link, "http://example.com")
         self.assertEqual(proposition.user, user.profile)
-        self.assertEqual(proposition.nb_yes, 0)
-        self.assertEqual(proposition.nb_no, 0)
 
 
 class PropositionListTest(TestCase):
@@ -99,11 +97,13 @@ class ReponseTest(TestCase):
         # Oui
         client.get(reverse("propositions:oui", args=(self.prop.id,)))
         self.prop.refresh_from_db()
-        self.assertEqual(self.prop.nb_yes, 1)
-        self.assertEqual(self.prop.nb_no, 0)
+        self.assertEqual(
+            list(self.prop.answer_set.values_list("answer", flat=True)), [Answer.YES],
+        )
 
         # Oui
         client.get(reverse("propositions:non", args=(self.prop.id,)))
         self.prop.refresh_from_db()
-        self.assertEqual(self.prop.nb_yes, 0)
-        self.assertEqual(self.prop.nb_no, 1)
+        self.assertEqual(
+            list(self.prop.answer_set.values_list("answer", flat=True)), [Answer.NO]
+        )
diff --git a/propositions/urls.py b/propositions/urls.py
index f08c0c3..efa172e 100644
--- a/propositions/urls.py
+++ b/propositions/urls.py
@@ -8,7 +8,7 @@ app_name = "propositions"
 urlpatterns = [
     path("", views.PropositionList.as_view(), name="list"),
     path("new", views.PropositionCreate.as_view(), name="create"),
-    path("<int:id>/oui", views.answer, {"rep": "oui"}, name=Answer.YES),
-    path("<int:id>/non", views.answer, {"rep": "non"}, name=Answer.NO),
+    path("<int:id>/oui", views.answer, {"ans": "oui"}, name=Answer.YES),
+    path("<int:id>/non", views.answer, {"ans": "non"}, name=Answer.NO),
     path("<int:pk>/supprimer", PropDelete.as_view(), name="delete"),
 ]
diff --git a/propositions/views.py b/propositions/views.py
index b7e8506..fc60316 100644
--- a/propositions/views.py
+++ b/propositions/views.py
@@ -2,6 +2,7 @@ from django.shortcuts import redirect, get_object_or_404
 from django.urls import reverse_lazy
 from django.contrib.auth.decorators import login_required
 from django.contrib.auth.mixins import LoginRequiredMixin
+from django.db.models import Count, Q
 from django.views.generic import CreateView, DeleteView, ListView
 from django.utils.decorators import method_decorator
 from django.http import HttpResponseRedirect
@@ -26,7 +27,14 @@ class PropositionList(LoginRequiredMixin, ListView):
     template_name = "propositions/liste.html"
     context_object_name = "propositions"
     model = Proposition
-    ordering = ["-nb_yes", "nb_no", "name"]
+
+    def get_queryset(self):
+        return (
+            Proposition.objects
+            .annotate(nb_yes=Count("answer", filter=Q(answer__answer=Answer.YES)))
+            .annotate(nb_no=Count("answer", filter=Q(answer__answer=Answer.NO)))
+            .order_by("-nb_yes", "nb_no", "name")
+        )
 
 
 class PropDelete(DeleteView):
@@ -50,24 +58,9 @@ class PropDelete(DeleteView):
 
 
 @login_required
-def answer(request, id, rep):
+def answer(request, id, ans):
     proposition = get_object_or_404(Proposition, id=id)
     user = request.user
-
-    old_answer = Answer.objects.filter(proposition=proposition, user=user)
-    if old_answer.exists():
-        old_answer = old_answer.get()
-        if old_answer.answer == Answer.YES:
-            proposition.nb_yes -= 1
-        else:
-            proposition.nb_no -= 1
-        old_answer.delete()
-
-    Answer.objects.create(proposition=proposition, user=user, answer=rep)
-    if rep == Answer.YES:
-        proposition.nb_yes += 1
-    else:
-        proposition.nb_no += 1
-    proposition.save()
-
+    Answer.objects.filter(proposition=proposition, user=user).delete()
+    Answer.objects.create(proposition=proposition, user=user, answer=ans)
     return redirect("propositions:list")