87.52% is the change from 521 to 977
Calculation steps:
[( 977 - 521 ) ÷ 521] x 100 = 87.52%
Formula
Percentage change = [(977 - 521) / 521] x 100
Subtract the new number by the original number
977 - 521 = 456
456 ÷ 521 = 0.8752399232245681
0.8752399232245681 x 100 = 87.52%