condition mean min max ZT0-3 4.29308 4.26343 4.3418600000000005 ZT4-7 3.16988 3.16988 3.16988 ZT8-11 2.196695 2.196695 2.196695 ZT12-15 2.5045475 2.09945 2.9096450000000003 ZT16-19 3.14114 3.14114 3.14114 ZT20-23 4.563345 4.563345 4.563345