condition mean min max ZT0-3 3.529856666666667 2.0770049999999998 4.99741 ZT4-7 1.9315950000000002 1.9315950000000002 1.9315950000000002 ZT8-11 3.98502 3.98502 3.98502 ZT12-15 12.357912500000001 9.287475 15.428350000000002 ZT16-19 14.94458 14.94458 14.94458 ZT20-23 7.8061300000000005 7.8061300000000005 7.8061300000000005