condition mean min max ZT0-3 3.4209071727500002 2.6917220860000004 4.1500922595 ZT4-7 5.50784551175 4.7125444805 6.3031465429999995 ZT8-11 7.0770884700000005 6.107029024500001 8.0471479155 ZT12-15 7.936667745 6.9966833600000005 8.87665213 ZT16-19 9.626532821 8.59616449 10.656901152 ZT20-23 13.839159949999999 12.664285405000001 15.014034494999999