-2.11% is the change from 521 to 510
Calculation steps:
[( 510 - 521 ) ÷ 521] x 100 = -2.11%
Formula
Percentage change = [(510 - 521) / 521] x 100
Subtract the new number by the original number
510 - 521 = -11
-11 ÷ 521 = -0.02111324376199616
-0.02111324376199616 x 100 = -2.11%