64.3% is the change from 521 to 856
Calculation steps:
[( 856 - 521 ) ÷ 521] x 100 = 64.3%
Formula
Percentage change = [(856 - 521) / 521] x 100
Subtract the new number by the original number
856 - 521 = 335
335 ÷ 521 = 0.6429942418426103
0.6429942418426103 x 100 = 64.3%