condition mean min max ZT0-3 2.257665 1.988995 2.73507 ZT4-7 13.059149999999999 13.059149999999999 13.059149999999999 ZT8-11 37.65325 37.65325 37.65325 ZT12-15 30.379175000000004 27.96885 32.789500000000004 ZT16-19 19.12565 19.12565 19.12565 ZT20-23 6.193355 6.193355 6.193355