-49.9% is the change from 521 to 261
Calculation steps:
[( 261 - 521 ) ÷ 521] x 100 = -49.9%
Formula
Percentage change = [(261 - 521) / 521] x 100
Subtract the new number by the original number
261 - 521 = -260
-260 ÷ 521 = -0.4990403071017274
-0.4990403071017274 x 100 = -49.9%