condition mean min max ZT0-3 1.648356 1.177548 1.958105 ZT4-7 1.87895 1.87895 1.87895 ZT8-11 1.752865 1.752865 1.752865 ZT12-15 6.134805 5.761335 6.508275 ZT16-19 5.056615 5.056615 5.056615 ZT20-23 3.625605 3.625605 3.625605