condition mean min max ZT0-3 2.0667925 1.93846 2.195125 ZT4-7 1.804085 1.804085 1.804085 ZT8-11 4.968505 4.968505 4.968505 ZT12-15 0 0 0 ZT16-19 3.6178350000000004 3.6178350000000004 3.6178350000000004 ZT20-23 2.29256 2.29256 2.29256