condition mean min max ZT0-3 216.4930094 190.1169793 242.8690395 ZT4-7 116.51055765 116.24247224999999 116.77864305 ZT8-11 57.1054902625 37.99818593 76.21279459499999 ZT12-15 5.4522575492500005 3.0198575515 7.884657547000001 ZT16-19 10.10244215975 7.419574904 12.785309415499999 ZT20-23 17.9063552525 17.29506827 18.517642234999997