34.15% is the change from 612 to 821
Calculation steps:
[( 821 - 612 ) ÷ 612] x 100 = 34.15%
Formula
Percentage change = [(821 - 612) / 612] x 100
Subtract the new number by the original number
821 - 612 = 209
209 ÷ 612 = 0.3415032679738562
0.3415032679738562 x 100 = 34.15%