-41.27% is the change from 521 to 306
Calculation steps:
[( 306 - 521 ) ÷ 521] x 100 = -41.27%
Formula
Percentage change = [(306 - 521) / 521] x 100
Subtract the new number by the original number
306 - 521 = -215
-215 ÷ 521 = -0.4126679462571977
-0.4126679462571977 x 100 = -41.27%