condition mean min max ZT0-3 9.832893333333333 9.832893333333333 9.832893333333333 ZT4-7 7.834490000000001 7.834490000000001 7.834490000000001 ZT8-11 4.456195 4.456195 4.456195 ZT12-15 4.40471 4.40471 4.40471 ZT16-19 5.71828 5.71828 5.71828 ZT20-23 6.91709 6.91709 6.91709