Fix axes steps count.

src/lib/components/test_cases/TestCasesPane.svelte

@@ -44,7 +44,7 @@
       }
 
       const axis = {
-        count: 100,
+        count: 101,
         index:
           previousSituationsPopulationCount +
           indexOfSituationPopulationId(
@@ -52,7 +52,7 @@
             $testCases[situationIndex],
             axisDescription.populationId,
           ),
-        max: (100 - 1) * axisDescription.stepValue,
+        max: (101 - 1) * axisDescription.stepValue,
         min: 0,
         name: axisDescription.variableName,
         period: year.toString(),