45.12% is the change from 215 to 312
Calculation steps:
[( 312 - 215 ) ÷ 215] x 100 = 45.12%
Formula
Percentage change = [(312 - 215) / 215] x 100
Subtract the new number by the original number
312 - 215 = 97
97 ÷ 215 = 0.4511627906976744
0.4511627906976744 x 100 = 45.12%