condition mean min max ZT0-3 3.2532550000000002 2.729895 3.776615 ZT4-7 3.75799 3.75799 3.75799 ZT8-11 9.16559 9.16559 9.16559 ZT12-15 0 0 0 ZT16-19 7.1718150000000005 7.1718150000000005 7.1718150000000005 ZT20-23 4.45871 4.45871 4.45871