condition mean min max ZT0-3 2.8499999999999996 2.8499999999999996 2.8499999999999996 ZT4-7 2.2 2.2 2.2 ZT8-11 3.8 3.8 3.8 ZT12-15 2.55 2.55 2.55 ZT16-19 3.8499999999999996 3.8499999999999996 3.8499999999999996 ZT20-23 3.4499999999999997 3.4499999999999997 3.4499999999999997