-66% is the change from 1000 to 340
Calculation steps:
[( 340 - 1000 ) ÷ 1000] x 100 = -66%
Formula
Percentage change = [(340 - 1000) / 1000] x 100
Subtract the new number by the original number
340 - 1000 = -660
-660 ÷ 1000 = -0.66
-0.66 x 100 = -66%