66.54% is the change from 520 to 866
Calculation steps:
[( 866 - 520 ) ÷ 520] x 100 = 66.54%
Formula
Percentage change = [(866 - 520) / 520] x 100
Subtract the new number by the original number
866 - 520 = 346
346 ÷ 520 = 0.6653846153846154
0.6653846153846154 x 100 = 66.54%