GSTR-4, Section 3, Aggregate Turnover

Was a Regular Dealer till 31/03/2019. Opted for Composition wef 01/04/2019.

While filing Annual GSTR-4 for FY 2019-20, Sec 3 asks for Aggregate Turnover for Previous FY

1. Does it mean Turnover for FY 2018-19?

2. Which amt should be mentioned... Total Invoice Value ?...or Taxable Value ? (was under Regular till 31/03/209)