We can solve this question with little logic.
The % increase would be maximum when the difference is more and denominator less

For example;
we can notice the maximum increase for 1992-1993 and 1996-1997
No doubt the difference is more for 1996-1997, but we will be dividing it by a larger value - which decreases the overall value

1992 = 30
1993 = 60
Difference = 30
% inc. = \(\frac{30}{30}(100) = 100\)%

1996 = 70
1997 = 120
Difference = 50
% inc. = \(\frac{50}{70}(100) = 71.42\)%

Hence, option A