How can I get right value?

Hello all sirs.

My question as blow :

I want use Rule Output / WIP = Overall Turn rate history. but why I use C column Calculate value it's different Overall turn rate history value???????

C = CALCULATE(DIVIDE(SUM('WAITING_TIME_REPORT_HISTORY'[Rule Output]),SUM('WAITING_TIME_REPORT_HISTORY'[WIP])),ALLEXCEPT(WAITING_TIME_REPORT_HISTORY,WAITING_TIME_REPORT_HISTORY[GROUP_PROCESS]))

Overall Turn rate history =
DIVIDE(
SUM('WAITING_TIME_REPORT_HISTORY'[Rule Output]),
SUM('WAITING_TIME_REPORT_HISTORY'[WIP])
)