condition mean min max ZT0-3 6.062243470249999 5.4731562154999995 6.651330725 ZT4-7 8.98311789225 6.8688333425 11.097402442 ZT8-11 14.7996473575 14.64101805 14.958276665 ZT12-15 16.475479352500003 16.082948295 16.86801041 ZT16-19 22.739399497500003 20.391775565 25.087023430000002 ZT20-23 30.95238338 28.896329265 33.008437495