condition mean min max ZT0-3 4.829355 4.829355 4.829355 ZT4-7 3.919035 3.919035 3.919035 ZT8-11 4.792025 4.792025 4.792025 ZT12-15 5.261675 5.261675 5.261675 ZT16-19 8.048179999999999 8.048179999999999 8.048179999999999 ZT20-23 5.723739999999999 5.723739999999999 5.723739999999999