condition mean min max ZT0-3 2.9216164427500004 2.179604068 3.6636288175000002 ZT4-7 6.3522156515 4.7517048084999995 7.9527264945 ZT8-11 8.519800736 8.1560464015 8.8835550705 ZT12-15 17.368944360249998 11.983332040499999 22.75455668 ZT16-19 22.0502311875 20.028853005000002 24.071609369999997 ZT20-23 26.326339635 24.73483543 27.91784384