condition mean min max ZT0-3 3.946895 3.946895 3.946895 ZT4-7 5.036325 5.036325 5.036325 ZT8-11 4.895725 4.895725 4.895725 ZT12-15 8.436915 8.436915 8.436915 ZT16-19 4.70828 4.70828 4.70828 ZT20-23 5.152685 5.152685 5.152685