-3.05% is the change from 950 to 921
Calculation steps:
[( 921 - 950 ) ÷ 950] x 100 = -3.05%
Formula
Percentage change = [(921 - 950) / 950] x 100
Subtract the new number by the original number
921 - 950 = -29
-29 ÷ 950 = -0.030526315789473683
-0.030526315789473683 x 100 = -3.05%