Filing of income tax returns surged 75.98 per cent in the current assessment year, with as many as 52.97 million people filing returns till about five hours before the deadline. The previous year, 30.1 million had filed returns. The high number, which might still go up, may help the government defend its decision to demonetise Rs 500 and Rs 1,000 in November 8, 2016. The government had extended the deadline to file return till August 31. For Kerala, affected by floods, it has been extended by another fortnight.