condition mean min max ZT0-3 0.4700784945 0.42029383899999995 0.51986315 ZT4-7 1.0814031317500001 0.500952101 1.6618541625 ZT8-11 6.018584979250001 4.093304464000001 7.943865494500001 ZT12-15 7.799234019500001 7.499760241500001 8.098707797500001 ZT16-19 6.9225226617499995 6.76802019 7.077025133499999 ZT20-23 6.518555583 6.323746352000001 6.713364814