6400% is the change from 15 to 975
Calculation steps:
[( 975 - 15 ) ÷ 15] x 100 = 6400%
Formula
Percentage change = [(975 - 15) / 15] x 100
Subtract the new number by the original number
975 - 15 = 960
960 ÷ 15 = 64
64 x 100 = 6400%
Example