-49.9% is the change from 515 to 258
Calculation steps:
[( 258 - 515 ) ÷ 515] x 100 = -49.9%
Formula
Percentage change = [(258 - 515) / 515] x 100
Subtract the new number by the original number
258 - 515 = -257
-257 ÷ 515 = -0.49902912621359224
-0.49902912621359224 x 100 = -49.9%