condition mean min max ZT0-3 1.65959229125 1.5445745135 1.774610069 ZT4-7 9.12671968 6.448738737 11.804700623 ZT8-11 11.2155832075 10.934717945 11.49644847 ZT12-15 6.650396615750001 5.7047673505 7.596025881000001 ZT16-19 4.216698587 3.6605169595 4.772880214500001 ZT20-23 1.5727806260000001 0.9075590499999999 2.238002202