condition mean min max ZT0-3 6.737550000000001 6.737550000000001 6.737550000000001 ZT4-7 5.352775 5.352775 5.352775 ZT8-11 6.97351 6.97351 6.97351 ZT12-15 7.100474999999999 7.100474999999999 7.100474999999999 ZT16-19 7.964295 7.964295 7.964295 ZT20-23 6.75475 6.75475 6.75475