condition mean min max ZT0-3 6.810175 3.1333450000000003 9.171825 ZT4-7 5.81903 5.81903 5.81903 ZT8-11 8.493305 8.493305 8.493305 ZT12-15 12.487549999999999 11.9682 13.0069 ZT16-19 15.247 15.247 15.247 ZT20-23 14.9031 14.9031 14.9031