condition mean min max ZT0-3 22.74928333333333 17.926299999999998 25.73255 ZT4-7 13.376999999999999 13.376999999999999 13.376999999999999 ZT8-11 13.1083 13.1083 13.1083 ZT12-15 21.366675 19.7125 23.020850000000003 ZT16-19 26.3746 26.3746 26.3746 ZT20-23 31.62115 31.62115 31.62115