Yes i realised you asked the question later on. Edited my comment.
Also, the difference between the 2 films is 16cr GROSS, not nett. in 1997-98, 16cr Gross films had around 85lakhs footfalls.
I am just speculating about increase in ticket prices since the ATP for KKHH is Rs. 22, which is more than the yearly ATP of 1998 of Rs 19.
Or just assume that BOI messed up.