condition mean min max ZT0-3 4.69320695925 3.3989419645000005 5.987471954 ZT4-7 3.387917667 2.6995142365 4.0763210975 ZT8-11 4.5061761444999995 3.9566440765 5.0557082125 ZT12-15 3.94822794 3.794314239 4.102141641 ZT16-19 2.4243841375 2.278927501 2.569840774 ZT20-23 2.506408989 2.4977635715 2.5150544065