100% is the change from 156 to 312
Calculation steps:
[( 312 - 156 ) ÷ 156] x 100 = 100%
Formula
Percentage change = [(312 - 156) / 156] x 100
Subtract the new number by the original number
312 - 156 = 156
156 ÷ 156 = 1
1 x 100 = 100%
Example