-71.91% is the change from 915 to 257
Calculation steps:
[( 257 - 915 ) ÷ 915] x 100 = -71.91%
Formula
Percentage change = [(257 - 915) / 915] x 100
Subtract the new number by the original number
257 - 915 = -658
-658 ÷ 915 = -0.7191256830601093
-0.7191256830601093 x 100 = -71.91%