307.5% is the change from 200 to 815
Calculation steps:
[( 815 - 200 ) ÷ 200] x 100 = 307.5%
Formula
Percentage change = [(815 - 200) / 200] x 100
Subtract the new number by the original number
815 - 200 = 615
615 ÷ 200 = 3.075
3.075 x 100 = 307.5%
Example