condition mean min max ZT0-3 3.15063 3.15063 3.15063 ZT4-7 2.96963 2.96963 2.96963 ZT8-11 3.543625 3.543625 3.543625 ZT12-15 2.975885 2.975885 2.975885 ZT16-19 3.075855 3.075855 3.075855 ZT20-23 2.547575 2.547575 2.547575