1900% is the change from 2 to 40
Calculation steps:
[( 40 - 2 ) ÷ 2] x 100 = 1900%
Formula
Percentage change = [(40 - 2) / 2] x 100
Subtract the new number by the original number
40 - 2 = 38
38 ÷ 2 = 19
19 x 100 = 1900%
Example