condition mean min max ZT0-3 6.31501 5.713015 6.917005 ZT4-7 9.93617 9.93617 9.93617 ZT8-11 10.36279 10.36279 10.36279 ZT12-15 0 0 0 ZT16-19 8.379685 8.379685 8.379685 ZT20-23 9.38065 9.38065 9.38065