condition mean min max ZT0-3 16.057138306 10.052033942 22.06224267 ZT4-7 7.6751321205 6.5712345585000005 8.7790296825 ZT8-11 7.43178268525 7.1863812275 7.677184143 ZT12-15 5.06375893825 4.727831875 5.3996860015 ZT16-19 4.705991270249999 4.3250709755 5.086911564999999 ZT20-23 6.50086294825 6.3952705530000005 6.6064553434999995