condition mean min max ZT0-3 18.216875 16.23335 20.200400000000002 ZT4-7 10.24075 10.24075 10.24075 ZT8-11 11.94599 11.94599 11.94599 ZT12-15 0 0 0 ZT16-19 34.44755 34.44755 34.44755 ZT20-23 23.6403 23.6403 23.6403