condition mean min max ZT0-3 273.130477 273.130477 273.130477 ZT4-7 180.37120750000003 180.37120750000003 180.37120750000003 ZT8-11 215.67112400000002 215.67112400000002 215.67112400000002 ZT12-15 268.383096 268.383096 268.383096 ZT16-19 423.2761425 423.2761425 423.2761425 ZT20-23 413.3801595 413.3801595 413.3801595