-3.3% is the change from 667 to 645
Calculation steps:
[( 645 - 667 ) ÷ 667] x 100 = -3.3%
Formula
Percentage change = [(645 - 667) / 667] x 100
Subtract the new number by the original number
645 - 667 = -22
-22 ÷ 667 = -0.03298350824587706
-0.03298350824587706 x 100 = -3.3%