condition mean min max ZT0-3 2.1480565 1.6419130000000002 2.6542 ZT4-7 1.90411 1.90411 1.90411 ZT8-11 2.65645 2.65645 2.65645 ZT12-15 0 0 0 ZT16-19 3.915015 3.915015 3.915015 ZT20-23 2.56538 2.56538 2.56538