condition mean min max ZT0-3 162.114971 162.114971 162.114971 ZT4-7 248.1554525 248.1554525 248.1554525 ZT8-11 263.0205185 263.0205185 263.0205185 ZT12-15 253.05757899999998 253.05757899999998 253.05757899999998 ZT16-19 216.651915 216.651915 216.651915 ZT20-23 194.3609415 194.3609415 194.3609415