condition mean min max ZT0-3 11.564698 11.564698 11.564698 ZT4-7 12.24812 12.24812 12.24812 ZT8-11 9.757421 9.757421 9.757421 ZT12-15 10.6391305 10.6391305 10.6391305 ZT16-19 9.405720500000001 9.405720500000001 9.405720500000001 ZT20-23 10.1853695 10.1853695 10.1853695