66.99% is the change from 312 to 521
Calculation steps:
[( 521 - 312 ) ÷ 312] x 100 = 66.99%
Formula
Percentage change = [(521 - 312) / 312] x 100
Subtract the new number by the original number
521 - 312 = 209
209 ÷ 312 = 0.6698717948717948
0.6698717948717948 x 100 = 66.99%