condition mean min max ZT0-3 6.304138333333333 2.312285 9.77442 ZT4-7 3.271115 3.271115 3.271115 ZT8-11 3.2878550000000004 3.2878550000000004 3.2878550000000004 ZT12-15 5.518730000000001 5.1511700000000005 5.886290000000001 ZT16-19 6.32524 6.32524 6.32524 ZT20-23 10.510825 10.510825 10.510825