condition mean min max ZT0-3 574.481576 574.481576 574.481576 ZT4-7 745.207413 745.207413 745.207413 ZT8-11 651.669574 651.669574 651.669574 ZT12-15 631.206824 631.206824 631.206824 ZT16-19 510.8987825 510.8987825 510.8987825 ZT20-23 374.773553 374.773553 374.773553