condition mean min max ZT0-3 4.36818 4.36818 4.36818 ZT4-7 4.30335 4.30335 4.30335 ZT8-11 3.9188650000000003 3.9188650000000003 3.9188650000000003 ZT12-15 3.80889 3.80889 3.80889 ZT16-19 5.50734 5.50734 5.50734 ZT20-23 5.75457 5.75457 5.75457