condition mean min max ZT0-3 1.6710566666666666 1.5823 1.811715 ZT4-7 0.7922715 0.7922715 0.7922715 ZT8-11 1.628775 1.628775 1.628775 ZT12-15 3.8533975000000003 3.1390450000000003 4.56775 ZT16-19 3.202835 3.202835 3.202835 ZT20-23 2.5744999999999996 2.5744999999999996 2.5744999999999996