condition mean min max ZT0-3 2.8 2.8 2.8 ZT4-7 5.4 5.4 5.4 ZT8-11 5.1 5.1 5.1 ZT12-15 2.8 2.8 2.8 ZT16-19 23.900000000000002 23.900000000000002 23.900000000000002 ZT20-23 2.3499999999999996 2.3499999999999996 2.3499999999999996