-1.6% is the change from 813 to 800
Calculation steps:
[( 800 - 813 ) ÷ 813] x 100 = -1.6%
Formula
Percentage change = [(800 - 813) / 813] x 100
Subtract the new number by the original number
800 - 813 = -13
-13 ÷ 813 = -0.015990159901599015
-0.015990159901599015 x 100 = -1.6%