condition mean min max ZT0-3 2.2567683333333335 1.429065 2.6782700000000004 ZT4-7 1.29688 1.29688 1.29688 ZT8-11 2.479895 2.479895 2.479895 ZT12-15 3.472065 3.114885 3.8292450000000002 ZT16-19 4.84898 4.84898 4.84898 ZT20-23 4.2251650000000005 4.2251650000000005 4.2251650000000005