-2.7% is the change from 555 to 540
Calculation steps:
[( 540 - 555 ) ÷ 555] x 100 = -2.7%
Formula
Percentage change = [(540 - 555) / 555] x 100
Subtract the new number by the original number
540 - 555 = -15
-15 ÷ 555 = -0.02702702702702703
-0.02702702702702703 x 100 = -2.7%