-1.64% is the change from 915 to 900
Calculation steps:
[( 900 - 915 ) ÷ 915] x 100 = -1.64%
Formula
Percentage change = [(900 - 915) / 915] x 100
Subtract the new number by the original number
900 - 915 = -15
-15 ÷ 915 = -0.01639344262295082
-0.01639344262295082 x 100 = -1.64%