condition mean min max ZT0-3 297.513913 297.513913 297.513913 ZT4-7 279.76732749999996 279.76732749999996 279.76732749999996 ZT8-11 237.210324 237.210324 237.210324 ZT12-15 241.437746 241.437746 241.437746 ZT16-19 249.80611299999998 249.80611299999998 249.80611299999998 ZT20-23 309.790206 309.790206 309.790206