66.6% is the change from 521 to 868
Calculation steps:
[( 868 - 521 ) ÷ 521] x 100 = 66.6%
Formula
Percentage change = [(868 - 521) / 521] x 100
Subtract the new number by the original number
868 - 521 = 347
347 ÷ 521 = 0.6660268714011516
0.6660268714011516 x 100 = 66.6%