-6.66% is the change from 691 to 645
Calculation steps:
[( 645 - 691 ) ÷ 691] x 100 = -6.66%
Formula
Percentage change = [(645 - 691) / 691] x 100
Subtract the new number by the original number
645 - 691 = -46
-46 ÷ 691 = -0.06657018813314038
-0.06657018813314038 x 100 = -6.66%