turnover gat r4

a person start his business from 1 jan 2016 . he have no tin no.so not filed vat return.but last year he take gst no composition scheme gstr4 on 1 july 2017.he file returns according to sale purchage.his sale from 1 july 2017 to 31 march 2018 is 2100000 as shown in gst site but my query is now when he filed gstr4 return of this financial year .then wht turnover he show in return of providing financial year. 1 april 2018 to 31 march 2019