66.88% is the change from 320 to 534
Calculation steps:
[( 534 - 320 ) ÷ 320] x 100 = 66.88%
Formula
Percentage change = [(534 - 320) / 320] x 100
Subtract the new number by the original number
534 - 320 = 214
214 ÷ 320 = 0.66875
0.66875 x 100 = 66.88%