The nth term of an arithmetic sequence is found from:

Plugging in the given values, we get for the 13th term:
-58=14+12d
12d =-58 - 14 = -72
d = -6
So, the 32nd term is:
85/100 is greater
85/100=.85 or 85%
21/25=.84 or 84%
.85 is greater than .84 so 85/100 > 21/25
The previous population was 14000.
Explanation
The population decreased by 35% since the last measurement. So the current population is less than the previous population.
current population=9100
previous population =x
current population is 35% less than the previous population x

The previous population was 14000.