-3.6% is the change from 667 to 643
Calculation steps:
[( 643 - 667 ) ÷ 667] x 100 = -3.6%
Formula
Percentage change = [(643 - 667) / 667] x 100
Subtract the new number by the original number
643 - 667 = -24
-24 ÷ 667 = -0.035982008995502246
-0.035982008995502246 x 100 = -3.6%