-6.23% is the change from 915 to 858
Calculation steps:
[( 858 - 915 ) ÷ 915] x 100 = -6.23%
Formula
Percentage change = [(858 - 915) / 915] x 100
Subtract the new number by the original number
858 - 915 = -57
-57 ÷ 915 = -0.06229508196721312
-0.06229508196721312 x 100 = -6.23%