condition mean min max ZT0-3 18.82525 18.82525 18.82525 ZT4-7 14.11495 14.11495 14.11495 ZT8-11 10.361925 10.361925 10.361925 ZT12-15 6.31138 6.31138 6.31138 ZT16-19 9.882964999999999 9.882964999999999 9.882964999999999 ZT20-23 17.5545 17.5545 17.5545