condition mean min max ZT0-3 16.60335 16.60335 16.60335 ZT4-7 9.256225 9.256225 9.256225 ZT8-11 14.7897 14.7897 14.7897 ZT12-15 17.36325 17.36325 17.36325 ZT16-19 20.3604 20.3604 20.3604 ZT20-23 20.887900000000002 20.887900000000002 20.887900000000002