38.29% is the change from 666 to 921
Calculation steps:
[( 921 - 666 ) ÷ 666] x 100 = 38.29%
Formula
Percentage change = [(921 - 666) / 666] x 100
Subtract the new number by the original number
921 - 666 = 255
255 ÷ 666 = 0.38288288288288286
0.38288288288288286 x 100 = 38.29%