condition mean min max ZT0-3 2.46566 2.4512 2.4801200000000003 ZT4-7 2.28253 2.28253 2.28253 ZT8-11 1.7082 1.7082 1.7082 ZT12-15 1.731246 1.629632 1.83286 ZT16-19 3.1166866666666664 2.99987 3.233503333333333 ZT20-23 0 0 0