-51.85% is the change from 27 to 13
Calculation steps:
[( 13 - 27 ) ÷ 27] x 100 = -51.85%
Formula
Percentage change = [(13 - 27) / 27] x 100
Subtract the new number by the original number
13 - 27 = -14
-14 ÷ 27 = -0.5185185185185185
-0.5185185185185185 x 100 = -51.85%