condition mean min max ZT0-3 1.6120450000000002 1.6120450000000002 1.6120450000000002 ZT4-7 0.9368185 0.9368185 0.9368185 ZT8-11 1.397915 1.397915 1.397915 ZT12-15 2.71555 2.71555 2.71555 ZT16-19 3.2898300000000003 3.2898300000000003 3.2898300000000003 ZT20-23 2.11884 2.11884 2.11884