-36.2% is the change from 1000 to 638
Calculation steps:
[( 638 - 1000 ) ÷ 1000] x 100 = -36.2%
Formula
Percentage change = [(638 - 1000) / 1000] x 100
Subtract the new number by the original number
638 - 1000 = -362
-362 ÷ 1000 = -0.362
-0.362 x 100 = -36.2%