According to CME Daily Bulletin for GBP calls and puts, on 20180307 the maximum open interest for calls has been registered at 1390 and reached 3179. Change in open interest was +69. Given the current forward points value 3.65, FOREX target price would be 1.38964. Maximum open interest for puts has been at 1365 and has made 905. The FOREX target price is 1.36464.
See how to use Daily Option Expiry Levels at http://zentrade.online/use-daily-option-expiry-levels/.
Alternatively, find below distribution according to combined maximum volume and open interest.