condition mean min max ZT0-3 6.3560512545 5.297120241 7.414982267999999 ZT4-7 7.01663173825 5.9401144995 8.093148977 ZT8-11 7.0914486025 6.899240003 7.283657202 ZT12-15 8.4031209365 7.321269796500001 9.4849720765 ZT16-19 8.5387269975 6.706553356 10.370900638999998 ZT20-23 17.744694449999997 14.37922507 21.110163829999998