condition mean min max ZT0-3 14.984206 14.984206 14.984206 ZT4-7 14.682519 14.682519 14.682519 ZT8-11 15.136816 15.136816 15.136816 ZT12-15 13.875018 13.875018 13.875018 ZT16-19 14.121313 14.121313 14.121313 ZT20-23 17.2892595 17.2892595 17.2892595