India replaced its currency to wipe out illegal money stashes. Now the central bank says it didn’t work

99% of banknotes were returned after demonetisation, India's Reserve Bank said.

Source: https://www.washingtonpost.com/world/2018/08/29/india-replaced-its-currency-wipe-out-illegal-money-stashes-now-central-bank-says-it-didnt-work/