4.88% is the change from 615 to 645
Calculation steps:
[( 645 - 615 ) ÷ 615] x 100 = 4.88%
Formula
Percentage change = [(645 - 615) / 615] x 100
Subtract the new number by the original number
645 - 615 = 30
30 ÷ 615 = 0.04878048780487805
0.04878048780487805 x 100 = 4.88%