condition mean min max ZT0-3 1.132875829 0.806338261 1.459413397 ZT4-7 3.9023134205000005 3.1904468935000003 4.6141799475 ZT8-11 5.983803345749999 4.8147851125 7.152821578999999 ZT12-15 18.532086754749997 14.1754935495 22.888679959999997 ZT16-19 18.4258821775 17.339646195 19.51211816 ZT20-23 24.33697707 23.0118917 25.66206244