India's electorate has witnessed a nearly five-fold increase since the first general elections. From a little over 173 million in the first general elections held in 1951, just four years after the country became independent from the British, it has reached a record 814 million in the 2014 general elections, making it by far the largest body of people to vote in a free election anywhere in the world.
Here is the electorate size for the Lok Sabha elections held so far:
1951 --- 173,212,343
1957 --- 193,652,179
1962 --- 127,719,470
1967 --- 248,904,300
1971 --- 274,189,132
1977 --- 321,174,327
1980 --- 356,205,329
1984 ---- 379,540,608
1989 --- 498,906,129
1991 --- 498,363,801
1996 --- 592,572,288
1998 --- 605,880,192
1999 --- 619,536,847
2004 --- 671,487,930
2009 ---- 716,985,101
2014 ---- 814,591,184