condition mean min max ZT0-3 23.37989 23.37989 23.37989 ZT4-7 22.124509 22.124509 22.124509 ZT8-11 21.900188 21.900188 21.900188 ZT12-15 22.197934 22.197934 22.197934 ZT16-19 23.125565 23.125565 23.125565 ZT20-23 20.386185 20.386185 20.386185