condition mean min max ZT0-3 7.34731 7.34731 7.34731 ZT4-7 4.34895 4.34895 4.34895 ZT8-11 4.66078 4.66078 4.66078 ZT12-15 6.58995 6.58995 6.58995 ZT16-19 7.82357 7.82357 7.82357 ZT20-23 9.493945 9.493945 9.493945