diff --git a/lib/growth/score/scorer.ex b/lib/growth/score/scorer.ex
index 5767f38..9bf6c37 100644
--- a/lib/growth/score/scorer.ex
+++ b/lib/growth/score/scorer.ex
@@ -28,7 +28,7 @@ defmodule Growth.Score.Scorer do
         {precision, scores(indicator, growth, l, m, s)}
       end)
 
-    %{growth | results: [Map.new([{indicator.measure_name(), result}]) | growth.results]}
+    %{growth | results: Keyword.put(growth.results, indicator.measure_name(), result)}
   end
 
   @spec lms(Growth.t(), module()) :: [{String.t(), {number(), number(), number()}}]
@@ -42,9 +42,9 @@ defmodule Growth.Score.Scorer do
   """
   def lms(growth, indicator) do
     [
-      {growth.gender, "day", growth.age_in_days},
-      {growth.gender, "week", growth.age_in_weeks},
-      {growth.gender, "month", growth.age_in_months}
+      {growth.gender, :day, growth.age_in_days},
+      {growth.gender, :week, growth.age_in_weeks},
+      {growth.gender, :month, growth.age_in_months}
     ]
     |> Enum.map(fn {_, precision, _} = key ->
       case :ets.lookup(indicator, key) do