condition mean min max ZT0-3 3.03114135225 2.1863771835 3.8759055210000004 ZT4-7 3.8694715745 2.930061843 4.808881306 ZT8-11 7.4704387915 6.8630524565 8.0778251265 ZT12-15 7.8367381300000005 7.1853437174999994 8.4881325425 ZT16-19 4.94441366925 4.732804592500001 5.156022746 ZT20-23 6.95310360225 6.393671242 7.512535962499999