diff --git a/src/module/setChartData.js b/src/module/setChartData.js
index 797c6b5..23054c6 100644
--- a/src/module/setChartData.js
+++ b/src/module/setChartData.js
@@ -165,6 +165,7 @@ export function timeRange(minTime, maxTime, amount) {
  * @returns {Array<number>} An array of interpolated Y values.
  */
 export function yTimeRange(data, yAmount, yMax) {
+  if (yAmount <= 1) return data.map((d) => d.y);
   const yRange = [];
   const yGap = 1 / (yAmount - 1);