condition mean min max ZT0-3 2.50859993575 2.092276913 2.9249229585 ZT4-7 6.469681713 4.9828870525 7.9564763735 ZT8-11 11.8275356875 11.11056831 12.544503065 ZT12-15 9.630063396499999 9.2640966115 9.996030181499998 ZT16-19 9.708298194000001 8.370218783 11.046377605 ZT20-23 5.498700964499999 3.9650071835 7.0323947454999995