condition mean min max ZT0-3 3.4080725 2.687875 4.12827 ZT4-7 2.012845 2.012845 2.012845 ZT8-11 2.14617 2.14617 2.14617 ZT12-15 0 0 0 ZT16-19 3.0625999999999998 3.0625999999999998 3.0625999999999998 ZT20-23 1.730925 1.730925 1.730925