condition mean min max ZT0-3 3.4087663889999997 2.8807000819999997 3.9368326959999997 ZT4-7 4.153120748500001 3.5628614675000003 4.743380029500001 ZT8-11 7.856978827 6.8547359285 8.8592217255 ZT12-15 9.46464895525 8.0472617305 10.88203618 ZT16-19 9.2210794595 8.900686077500001 9.5414728415 ZT20-23 9.280483465249999 8.959901473999999 9.601065456499999