-59.9% is the change from 990 to 397
Calculation steps:
[( 397 - 990 ) ÷ 990] x 100 = -59.9%
Formula
Percentage change = [(397 - 990) / 990] x 100
Subtract the new number by the original number
397 - 990 = -593
-593 ÷ 990 = -0.598989898989899
-0.598989898989899 x 100 = -59.9%