condition mean min max ZT0-3 17.85838 17.85838 17.85838 ZT4-7 19.437338500000003 19.437338500000003 19.437338500000003 ZT8-11 19.3683635 19.3683635 19.3683635 ZT12-15 23.771318 23.771318 23.771318 ZT16-19 22.538055 22.538055 22.538055 ZT20-23 18.653090499999998 18.653090499999998 18.653090499999998