diff --git a/nextjs-app/components/PerformanceChart.tsx b/nextjs-app/components/PerformanceChart.tsx
index 79a2f7a..6978789 100644
--- a/nextjs-app/components/PerformanceChart.tsx
+++ b/nextjs-app/components/PerformanceChart.tsx
@@ -40,7 +40,11 @@ interface PerformanceChartProps {
 export function PerformanceChart({ data, schoolName, isSecondary = false }: PerformanceChartProps) {
   // Sort data by year
   const sortedData = [...data].sort((a, b) => a.year - b.year);
-  const years = sortedData.map(d => d.year.toString());
+  const formatYear = (y: number) => {
+    const s = y.toString();
+    return s.length === 6 ? `${s.slice(0, 4)}/${s.slice(4)}` : s;
+  };
+  const years = sortedData.map(d => formatYear(d.year));
 
   // Prepare datasets — phase-aware
   const datasets = isSecondary ? [