-0.6% is the change from 999 to 993
Calculation steps:
[( 993 - 999 ) ÷ 999] x 100 = -0.6%
Formula
Percentage change = [(993 - 999) / 999] x 100
Subtract the new number by the original number
993 - 999 = -6
-6 ÷ 999 = -0.006006006006006006
-0.006006006006006006 x 100 = -0.6%