condition mean min max ZT0-3 4.944195000000001 4.089840000000001 5.7985500000000005 ZT4-7 4.075525 4.075525 4.075525 ZT8-11 12.3887 12.3887 12.3887 ZT12-15 0 0 0 ZT16-19 9.706395 9.706395 9.706395 ZT20-23 7.05612 7.05612 7.05612