-27.43% is the change from 915 to 664
Calculation steps:
[( 664 - 915 ) ÷ 915] x 100 = -27.43%
Formula
Percentage change = [(664 - 915) / 915] x 100
Subtract the new number by the original number
664 - 915 = -251
-251 ÷ 915 = -0.2743169398907104
-0.2743169398907104 x 100 = -27.43%