condition mean min max ZT0-3 266.083986 266.083986 266.083986 ZT4-7 225.4160185 225.4160185 225.4160185 ZT8-11 292.1847285 292.1847285 292.1847285 ZT12-15 286.44835049999995 286.44835049999995 286.44835049999995 ZT16-19 335.39669649999996 335.39669649999996 335.39669649999996 ZT20-23 303.45722950000004 303.45722950000004 303.45722950000004