-68.54% is the change from 817 to 257
Calculation steps:
[( 257 - 817 ) ÷ 817] x 100 = -68.54%
Formula
Percentage change = [(257 - 817) / 817] x 100
Subtract the new number by the original number
257 - 817 = -560
-560 ÷ 817 = -0.6854345165238678
-0.6854345165238678 x 100 = -68.54%