Simplify the following text for a Grade 8 native English-speaking person.
Original: According to the 1998 census , the population of the city was 102,188 having increased from 61,447 at the 1981 census .
Simplified: At the 1998 census , the population of the city of Khairpur was 102,188 having increased from 61,447 at the 1981 census .