-36.45% is the change from 642 to 408
Calculation steps:
[( 408 - 642 ) ÷ 642] x 100 = -36.45%
Formula
Percentage change = [(408 - 642) / 642] x 100
Subtract the new number by the original number
408 - 642 = -234
-234 ÷ 642 = -0.3644859813084112
-0.3644859813084112 x 100 = -36.45%