condition mean min max ZT0-3 3.3020116666666666 2.44234 4.36023 ZT4-7 1.9863 1.9863 1.9863 ZT8-11 1.3420825 1.3420825 1.3420825 ZT12-15 5.8278725 4.566755 7.08899 ZT16-19 4.786465 4.786465 4.786465 ZT20-23 4.6726 4.6726 4.6726