condition mean min max ZT0-3 1.7596073333333333 1.7596073333333333 1.7596073333333333 ZT4-7 1.6971465000000001 1.6971465000000001 1.6971465000000001 ZT8-11 2.343895 2.343895 2.343895 ZT12-15 2.59608 2.59608 2.59608 ZT16-19 2.14886 2.14886 2.14886 ZT20-23 5.027335 5.027335 5.027335