-6.46% is the change from 666 to 623
Calculation steps:
[( 623 - 666 ) ÷ 666] x 100 = -6.46%
Formula
Percentage change = [(623 - 666) / 666] x 100
Subtract the new number by the original number
623 - 666 = -43
-43 ÷ 666 = -0.06456456456456457
-0.06456456456456457 x 100 = -6.46%