-51.26% is the change from 515 to 251
Calculation steps:
[( 251 - 515 ) ÷ 515] x 100 = -51.26%
Formula
Percentage change = [(251 - 515) / 515] x 100
Subtract the new number by the original number
251 - 515 = -264
-264 ÷ 515 = -0.512621359223301
-0.512621359223301 x 100 = -51.26%