condition mean min max ZT0-3 3.2550974999999998 2.812055 3.6981399999999995 ZT4-7 2.57533 2.57533 2.57533 ZT8-11 1.992215 1.992215 1.992215 ZT12-15 0 0 0 ZT16-19 2.52539 2.52539 2.52539 ZT20-23 3.8898200000000003 3.8898200000000003 3.8898200000000003