-17.79% is the change from 669 to 550
Calculation steps:
[( 550 - 669 ) ÷ 669] x 100 = -17.79%
Formula
Percentage change = [(550 - 669) / 669] x 100
Subtract the new number by the original number
550 - 669 = -119
-119 ÷ 669 = -0.17787742899850523
-0.17787742899850523 x 100 = -17.79%