34.63% is the change from 387 to 521
Calculation steps:
[( 521 - 387 ) ÷ 387] x 100 = 34.63%
Formula
Percentage change = [(521 - 387) / 387] x 100
Subtract the new number by the original number
521 - 387 = 134
134 ÷ 387 = 0.3462532299741602
0.3462532299741602 x 100 = 34.63%