71.38% is the change from 304 to 521
Calculation steps:
[( 521 - 304 ) ÷ 304] x 100 = 71.38%
Formula
Percentage change = [(521 - 304) / 304] x 100
Subtract the new number by the original number
521 - 304 = 217
217 ÷ 304 = 0.7138157894736842
0.7138157894736842 x 100 = 71.38%