condition mean min max ZT0-3 41.541755925 32.677415759999995 50.40609609 ZT4-7 20.13546291 19.531814675 20.739111145000003 ZT8-11 16.278350975000002 15.5091833 17.04751865 ZT12-15 16.717238355 15.79087269 17.64360402 ZT16-19 37.3087379425 35.380827135000004 39.23664875 ZT20-23 52.2665624925 48.107772225000005 56.425352759999996