condition mean min max ZT0-3 13.512062499999999 13.41739478 13.60673022 ZT4-7 3.2054480612500003 2.504732098 3.9061640245 ZT8-11 2.2988565024999996 1.9021087765 2.6956042284999997 ZT12-15 6.089340985750001 3.9460256210000004 8.232656350500001 ZT16-19 6.960886378 5.6721889945 8.2495837615 ZT20-23 13.4939953025 12.39653313 14.591457475