condition mean min max ZT0-3 2.10591082075 2.090886234 2.1209354075 ZT4-7 1.93740180725 1.284578614 2.5902250005000003 ZT8-11 4.596518503 3.4103287389999997 5.782708267 ZT12-15 11.394954839250001 7.6073797535 15.182529925 ZT16-19 12.3200191175 11.43394837 13.206089865 ZT20-23 15.001964962499999 13.829356959999998 16.174572965