condition mean min max ZT0-3 3.5418283333333336 2.647245 4.732865 ZT4-7 3.3552150000000003 3.3552150000000003 3.3552150000000003 ZT8-11 5.119540000000001 5.119540000000001 5.119540000000001 ZT12-15 8.8144275 8.727285 8.90157 ZT16-19 6.63762 6.63762 6.63762 ZT20-23 7.406874999999999 7.406874999999999 7.406874999999999