condition mean min max ZT0-3 13.858939 13.858939 13.858939 ZT4-7 12.6545445 12.6545445 12.6545445 ZT8-11 12.327141999999998 12.327141999999998 12.327141999999998 ZT12-15 10.788981499999998 10.788981499999998 10.788981499999998 ZT16-19 10.498899 10.498899 10.498899 ZT20-23 10.9235625 10.9235625 10.9235625