condition mean min max ZT0-3 11.170552 11.170552 11.170552 ZT4-7 8.008585 8.008585 8.008585 ZT8-11 10.510803 10.510803 10.510803 ZT12-15 10.386072500000001 10.386072500000001 10.386072500000001 ZT16-19 9.99466 9.99466 9.99466 ZT20-23 10.125257999999999 10.125257999999999 10.125257999999999