condition mean min max ZT0-3 9.1664502625 4.909201685 13.42369884 ZT4-7 7.828221736 7.280887891 8.375555581 ZT8-11 8.20670027975 5.478188611 10.935211948500001 ZT12-15 5.84255589825 5.0103403395 6.674771456999999 ZT16-19 4.21591316025 3.869641133 4.562185187500001 ZT20-23 2.72932885025 2.1759881835000003 3.282669517