condition mean min max ZT0-3 13.823374999999999 13.3149 14.33185 ZT4-7 15.37255 15.37255 15.37255 ZT8-11 20.641199999999998 20.641199999999998 20.641199999999998 ZT12-15 0 0 0 ZT16-19 25.4954 25.4954 25.4954 ZT20-23 21.83795 21.83795 21.83795