PCR calculation in special circumstances

I am using PCR on change in OI and not for OI. I am trying to use the system introduced by CA Nitin Murarka of SMC Global for this calculation. While computing PCR of Change in OI, I am facing a difficulty. If call OI change is increasing and put OI change is decreasing, because of the minus sign, the ratio completely shows reverse result than what it should be. How to compute PCR in such situations where one change in OI (call or put) is increasing while the other one is decreasing?