condition mean min max ZT0-3 203.415556 203.415556 203.415556 ZT4-7 199.7121275 199.7121275 199.7121275 ZT8-11 239.44732 239.44732 239.44732 ZT12-15 254.65950349999997 254.65950349999997 254.65950349999997 ZT16-19 300.674826 300.674826 300.674826 ZT20-23 293.7330845 293.7330845 293.7330845