condition mean min max ZT0-3 13.506954089 12.03409881 14.979809368000002 ZT4-7 3.4898086194999998 2.8985333559999997 4.081083883 ZT8-11 4.890254655 3.7590662665 6.0214430435 ZT12-15 6.667118920249999 5.973499115999999 7.360738724499999 ZT16-19 9.47193167475 7.345123978999999 11.598739370499999 ZT20-23 18.09948661 15.88026367 20.31870955