condition mean min max ZT0-3 4.9508875 4.61891 5.282865 ZT4-7 15.6636 15.6636 15.6636 ZT8-11 13.771550000000001 13.771550000000001 13.771550000000001 ZT12-15 0 0 0 ZT16-19 3.929805 3.929805 3.929805 ZT20-23 6.003295 6.003295 6.003295