-51.37% is the change from 512 to 249
Calculation steps:
[( 249 - 512 ) ÷ 512] x 100 = -51.37%
Formula
Percentage change = [(249 - 512) / 512] x 100
Subtract the new number by the original number
249 - 512 = -263
-263 ÷ 512 = -0.513671875
-0.513671875 x 100 = -51.37%