4.21% is the change from 950 to 990
Calculation steps:
[( 990 - 950 ) ÷ 950] x 100 = 4.21%
Formula
Percentage change = [(990 - 950) / 950] x 100
Subtract the new number by the original number
990 - 950 = 40
40 ÷ 950 = 0.042105263157894736
0.042105263157894736 x 100 = 4.21%