condition mean min max ZT0-3 4.378368333333333 2.848985 6.295025 ZT4-7 3.10328 3.10328 3.10328 ZT8-11 1.202275 1.202275 1.202275 ZT12-15 2.4348650000000003 2.28959 2.58014 ZT16-19 3.83574 3.83574 3.83574 ZT20-23 2.04204 2.04204 2.04204