-34.65% is the change from 990 to 647
Calculation steps:
[( 647 - 990 ) ÷ 990] x 100 = -34.65%
Formula
Percentage change = [(647 - 990) / 990] x 100
Subtract the new number by the original number
647 - 990 = -343
-343 ÷ 990 = -0.3464646464646465
-0.3464646464646465 x 100 = -34.65%