指數轉換為報酬率

請問如何將指數轉換為報酬率就是純粹將數值轉換為百分之多少我想將下列發行量加權股價指數轉換為報酬率須詳列公式或是在excel上的算法謝謝發行量加權股價報酬指數10052.169139995.79734.0454559388.6331828764.1558611.6526098110.1073918217.9927787142.3454556146.0713645585.84055583.6825610.1830435626.57956280.5118187702.8028578720.786198609.9909099693.14333310540.0866710501.860489983.273819462.6671439371.7886369828.78714310408.7854511361.0327310722.3405610310.3904310860.616829848.46159245.6436369136.6368790.799138937.7016678934.2118188723.2814298307.8813648036.097748.9542867452.6382617243.8485717206.6404557818.8480957618.7931587135.3173917259.87254.626111
一般算每一日的報酬率就是(今天指數-昨天指數)/昨天指數*100%所以若A1=發行量加權股價報酬指數A2=10052.16913A3=9995.7在B2計算10052.16913這天的大盤報酬率輸入(A2-A3)/A3*100%請參閱https://spreadsheets.google.com/ccc?key=tTvXQqqdY4ydnQnh1wBCaeg