condition mean min max ZT0-3 31.433650835 25.48660358 37.38069809 ZT4-7 8.5897390005 8.542442806 8.637035195 ZT8-11 8.495622946249998 7.7814586519999995 9.209787240499999 ZT12-15 11.45579165825 9.2268537115 13.684729605 ZT16-19 14.681254225 12.17476799 17.18774046 ZT20-23 32.64715573 27.436433795 37.857877665000004