-64.92% is the change from 915 to 321
Calculation steps:
[( 321 - 915 ) ÷ 915] x 100 = -64.92%
Formula
Percentage change = [(321 - 915) / 915] x 100
Subtract the new number by the original number
321 - 915 = -594
-594 ÷ 915 = -0.6491803278688525
-0.6491803278688525 x 100 = -64.92%