condition mean min max ZT0-3 4.365573333333333 3.9256849999999996 5.1302 ZT4-7 5.162380000000001 5.162380000000001 5.162380000000001 ZT8-11 4.549645 4.549645 4.549645 ZT12-15 6.5308150000000005 5.701055 7.360575 ZT16-19 5.2035599999999995 5.2035599999999995 5.2035599999999995 ZT20-23 5.47935 5.47935 5.47935