-2.8% is the change from 536 to 521
Calculation steps:
[( 521 - 536 ) ÷ 536] x 100 = -2.8%
Formula
Percentage change = [(521 - 536) / 536] x 100
Subtract the new number by the original number
521 - 536 = -15
-15 ÷ 536 = -0.027985074626865673
-0.027985074626865673 x 100 = -2.8%