condition mean min max ZT0-3 5.53049 4.650095 6.38987 ZT4-7 4.732385 4.732385 4.732385 ZT8-11 2.6473449999999996 2.6473449999999996 2.6473449999999996 ZT12-15 4.7367975 3.7446400000000004 5.728955 ZT16-19 5.19362 5.19362 5.19362 ZT20-23 5.323065 5.323065 5.323065