-67.18% is the change from 521 to 171
Calculation steps:
[( 171 - 521 ) ÷ 521] x 100 = -67.18%
Formula
Percentage change = [(171 - 521) / 521] x 100
Subtract the new number by the original number
171 - 521 = -350
-350 ÷ 521 = -0.6717850287907869
-0.6717850287907869 x 100 = -67.18%