From your link.
Partition was 1947. 

Pic1: In 1951, in Indian Punjab (then still incl Chandigarh, Haryana, HP, Delhi), Sikhism was not a 1/3 of the population and Hinduism was nearly 2/3s.

Pic2: How is it that Punjab by 1961 (still incl Haryana etc) had a majority Sikh pop?