condition mean min max ZT0-3 2.8693825000000004 2.3765650000000003 3.3622 ZT4-7 2.938865 2.938865 2.938865 ZT8-11 3.28539 3.28539 3.28539 ZT12-15 0 0 0 ZT16-19 1.891365 1.891365 1.891365 ZT20-23 2.685175 2.685175 2.685175