condition mean min max ZT0-3 4.26326 3.7003399999999997 4.75401 ZT4-7 5.601755 5.601755 5.601755 ZT8-11 2.96756 2.96756 2.96756 ZT12-15 2.3227725 1.917235 2.72831 ZT16-19 2.4753350000000003 2.4753350000000003 2.4753350000000003 ZT20-23 3.3675949999999997 3.3675949999999997 3.3675949999999997