condition mean min max ZT0-3 4.66479 4.28275 5.04683 ZT4-7 5.878915 5.878915 5.878915 ZT8-11 11.3041 11.3041 11.3041 ZT12-15 0 0 0 ZT16-19 11.319600000000001 11.319600000000001 11.319600000000001 ZT20-23 7.9692 7.9692 7.9692