-1.33% is the change from 830 to 819
Calculation steps:
[( 819 - 830 ) ÷ 830] x 100 = -1.33%
Formula
Percentage change = [(819 - 830) / 830] x 100
Subtract the new number by the original number
819 - 830 = -11
-11 ÷ 830 = -0.01325301204819277
-0.01325301204819277 x 100 = -1.33%