condition mean min max ZT0-3 3.4368583333333333 2.561645 3.9166 ZT4-7 3.147665 3.147665 3.147665 ZT8-11 3.923045 3.923045 3.923045 ZT12-15 8.1205 7.69158 8.54942 ZT16-19 5.961925 5.961925 5.961925 ZT20-23 5.980119999999999 5.980119999999999 5.980119999999999