condition mean min max ZT0-3 14.501475 14.47095 14.532 ZT4-7 13.966349999999998 13.966349999999998 13.966349999999998 ZT8-11 16.52665 16.52665 16.52665 ZT12-15 0 0 0 ZT16-19 19.457900000000002 19.457900000000002 19.457900000000002 ZT20-23 17.12895 17.12895 17.12895