6.62% is the change from 770 to 821
Calculation steps:
[( 821 - 770 ) ÷ 770] x 100 = 6.62%
Formula
Percentage change = [(821 - 770) / 770] x 100
Subtract the new number by the original number
821 - 770 = 51
51 ÷ 770 = 0.06623376623376623
0.06623376623376623 x 100 = 6.62%