condition mean min max ZT0-3 21.623897 21.623897 21.623897 ZT4-7 18.2432515 18.2432515 18.2432515 ZT8-11 18.516979 18.516979 18.516979 ZT12-15 18.5764455 18.5764455 18.5764455 ZT16-19 18.469179 18.469179 18.469179 ZT20-23 18.5303185 18.5303185 18.5303185