condition mean min max ZT0-3 3.8237319860000003 3.4534692430000002 4.193994729 ZT4-7 5.5673684505 5.1946910615 5.9400458395 ZT8-11 7.87195441325 6.714207299 9.0297015275 ZT12-15 9.63831806425 9.515754029 9.7608820995 ZT16-19 7.610087689249999 7.501710580499999 7.718464797999999 ZT20-23 7.78021543725 7.2152476055 8.345183269