condition mean min max ZT0-3 2.29272626825 1.487749917 3.0977026194999997 ZT4-7 5.293186101 4.117821026 6.468551176 ZT8-11 9.76032515325 7.898203711499999 11.622446595 ZT12-15 10.38393653375 10.087933268 10.6799397995 ZT16-19 4.9385360845 4.8237199775 5.0533521915 ZT20-23 3.349379508 2.816425444 3.882333572