diff --git a/src/index.js b/src/index.js
index 0c5edf1ba27ad381ff99a802e3b2a55d3f0e7d1a..61d8d58499b1e939b8a55838379d7346ef046d47 100644
--- a/src/index.js
+++ b/src/index.js
@@ -93,11 +93,12 @@ async function getData(response) {
     throw new Error(errors.VENDOR_DOWN)
   }
 }
+
 function format(response) {
-  const data = response.resultatRetour.map(value => {
+  const data = response.resultatRetour.slice(1).map((value, index) => {
     return {
       time: moment(value.DateReleve, moment.ISO_8601).format('YYYY-MM-DD'),
-      load: value.ValeurIndex,
+      load: value.ValeurIndex - response.resultatRetour[index].ValeurIndex,
       type: value.TypeAgregat
     }
   })