condition mean min max ZT0-3 20.676411666666667 9.2012 38.496700000000004 ZT4-7 4.66626 4.66626 4.66626 ZT8-11 18.953075000000002 18.953075000000002 18.953075000000002 ZT12-15 20.301975 15.7266 24.87735 ZT16-19 18.156579999999998 18.156579999999998 18.156579999999998 ZT20-23 30.4403 30.4403 30.4403