-2.51% is the change from 319 to 311
Calculation steps:
[( 311 - 319 ) ÷ 319] x 100 = -2.51%
Formula
Percentage change = [(311 - 319) / 319] x 100
Subtract the new number by the original number
311 - 319 = -8
-8 ÷ 319 = -0.025078369905956112
-0.025078369905956112 x 100 = -2.51%