-64.59% is the change from 257 to 91
Calculation steps:
[( 91 - 257 ) ÷ 257] x 100 = -64.59%
Formula
Percentage change = [(91 - 257) / 257] x 100
Subtract the new number by the original number
91 - 257 = -166
-166 ÷ 257 = -0.6459143968871596
-0.6459143968871596 x 100 = -64.59%