-60.9% is the change from 1000 to 391
Calculation steps:
[( 391 - 1000 ) ÷ 1000] x 100 = -60.9%
Formula
Percentage change = [(391 - 1000) / 1000] x 100
Subtract the new number by the original number
391 - 1000 = -609
-609 ÷ 1000 = -0.609
-0.609 x 100 = -60.9%