Price escalation with expression - Subscription Management

Hi,

I have use case for using CPI in subscription management as follows.

Previous CPI - 339

Current CPI - 367

CAP - 5%

CPI to calculated as Current_CPI-Previous CPI/Current CPI% and compare the result with CAP% which is 5.

I have converted this use case as below formula & updated in subscription. But it did not do anything.

CASE
WHEN NVL((({TM_US_CURRENT_PERIOD}-{TM_US_PREVIOUS_PERIOD})/{TM_US_PREVIOUS_PERIOD})*100,5) > 5
THEN NVL(((({TM_US_CURRENT_PERIOD}-{TM_US_PREVIOUS_PERIOD})/{TM_US_PREVIOUS_PERIOD})*100),5)
ELSE 5
END

Please suggest if this is correct or any other option to acieve this use case.