condition mean min max ZT0-3 24.22685 24.22685 24.22685 ZT4-7 23.5397 23.5397 23.5397 ZT8-11 13.41315 13.41315 13.41315 ZT12-15 12.22735 12.22735 12.22735 ZT16-19 18.2774 18.2774 18.2774 ZT20-23 29.6878 29.6878 29.6878