condition mean min max ZT0-3 6.8796173750000005 4.821230851 8.938003899 ZT4-7 22.1132449925 20.17831598 24.048174005 ZT8-11 29.4030331875 25.182509345 33.62355703 ZT12-15 48.44582756 39.865723095 57.025932025 ZT16-19 27.152997929999998 21.75127514 32.55472072 ZT20-23 12.455272822 11.639015169 13.271530474999999