-1.86% is the change from 215 to 211
Calculation steps:
[( 211 - 215 ) ÷ 215] x 100 = -1.86%
Formula
Percentage change = [(211 - 215) / 215] x 100
Subtract the new number by the original number
211 - 215 = -4
-4 ÷ 215 = -0.018604651162790697
-0.018604651162790697 x 100 = -1.86%