condition mean min max ZT0-3 4.335503034249999 3.475965397 5.195040671499999 ZT4-7 5.53852846375 4.857009485 6.2200474425 ZT8-11 6.47818078025 5.3771346895 7.5792268709999995 ZT12-15 11.22662960925 10.6004525535 11.852806665 ZT16-19 17.445574555 16.110908805 18.780240305 ZT20-23 20.087696049999998 19.6924153 20.4829768