70.23% is the change from 309 to 526
Calculation steps:
[( 526 - 309 ) ÷ 309] x 100 = 70.23%
Formula
Percentage change = [(526 - 309) / 309] x 100
Subtract the new number by the original number
526 - 309 = 217
217 ÷ 309 = 0.7022653721682848
0.7022653721682848 x 100 = 70.23%