condition mean min max ZT0-3 2.4893266666666665 1.76884 3.09041 ZT4-7 1.6438000000000001 1.6438000000000001 1.6438000000000001 ZT8-11 1.1784824999999999 1.1784824999999999 1.1784824999999999 ZT12-15 1.44109 1.362865 1.519315 ZT16-19 1.262495 1.262495 1.262495 ZT20-23 2.151505 2.151505 2.151505