condition mean min max ZT0-3 8.793485 8.793485 8.793485 ZT4-7 5.565300000000001 5.565300000000001 5.565300000000001 ZT8-11 5.98554 5.98554 5.98554 ZT12-15 5.980925 5.980925 5.980925 ZT16-19 11.5014 11.5014 11.5014 ZT20-23 10.690999999999999 10.690999999999999 10.690999999999999