-1.92% is the change from 521 to 511
Calculation steps:
[( 511 - 521 ) ÷ 521] x 100 = -1.92%
Formula
Percentage change = [(511 - 521) / 521] x 100
Subtract the new number by the original number
511 - 521 = -10
-10 ÷ 521 = -0.019193857965451054
-0.019193857965451054 x 100 = -1.92%