-2.66% is the change from 639 to 622
Calculation steps:
[( 622 - 639 ) ÷ 639] x 100 = -2.66%
Formula
Percentage change = [(622 - 639) / 639] x 100
Subtract the new number by the original number
622 - 639 = -17
-17 ÷ 639 = -0.026604068857589983
-0.026604068857589983 x 100 = -2.66%