condition mean min max ZT0-3 4.934695 4.934695 4.934695 ZT4-7 3.59449 3.59449 3.59449 ZT8-11 3.430595 3.430595 3.430595 ZT12-15 3.413175 3.413175 3.413175 ZT16-19 5.0589949999999995 5.0589949999999995 5.0589949999999995 ZT20-23 5.73424 5.73424 5.73424