condition mean min max ZT0-3 13.601484 13.601484 13.601484 ZT4-7 14.777182999999999 14.777182999999999 14.777182999999999 ZT8-11 12.4106005 12.4106005 12.4106005 ZT12-15 12.791579500000001 12.791579500000001 12.791579500000001 ZT16-19 14.060522500000001 14.060522500000001 14.060522500000001 ZT20-23 13.493013 13.493013 13.493013