condition mean min max ZT0-3 5.578595 5.578595 5.578595 ZT4-7 3.363455 3.363455 3.363455 ZT8-11 5.06355 5.06355 5.06355 ZT12-15 7.196199999999999 7.196199999999999 7.196199999999999 ZT16-19 9.354285 9.354285 9.354285 ZT20-23 7.388415 7.388415 7.388415