850% is the change from 18 to 171
Calculation steps:
[( 171 - 18 ) ÷ 18] x 100 = 850%
Formula
Percentage change = [(171 - 18) / 18] x 100
Subtract the new number by the original number
171 - 18 = 153
153 ÷ 18 = 8.5
8.5 x 100 = 850%
Example