67.6% is the change from 321 to 538
Calculation steps:
[( 538 - 321 ) ÷ 321] x 100 = 67.6%
Formula
Percentage change = [(538 - 321) / 321] x 100
Subtract the new number by the original number
538 - 321 = 217
217 ÷ 321 = 0.67601246105919
0.67601246105919 x 100 = 67.6%