-3.15% is the change from 951 to 921
Calculation steps:
[( 921 - 951 ) ÷ 951] x 100 = -3.15%
Formula
Percentage change = [(921 - 951) / 951] x 100
Subtract the new number by the original number
921 - 951 = -30
-30 ÷ 951 = -0.031545741324921134
-0.031545741324921134 x 100 = -3.15%