condition mean min max ZT0-3 7.498785 6.97706 8.02051 ZT4-7 17.4759 17.4759 17.4759 ZT8-11 5.936505 5.936505 5.936505 ZT12-15 0 0 0 ZT16-19 3.219425 3.219425 3.219425 ZT20-23 9.804675 9.804675 9.804675