condition mean min max ZT0-3 254.520649 254.520649 254.520649 ZT4-7 174.2765445 174.2765445 174.2765445 ZT8-11 236.1725485 236.1725485 236.1725485 ZT12-15 221.76412249999998 221.76412249999998 221.76412249999998 ZT16-19 270.159798 270.159798 270.159798 ZT20-23 225.831043 225.831043 225.831043