condition mean min max ZT0-3 15.9466 14.72735 17.16585 ZT4-7 11.9742 11.9742 11.9742 ZT8-11 12.6461 12.6461 12.6461 ZT12-15 0 0 0 ZT16-19 15.598700000000001 15.598700000000001 15.598700000000001 ZT20-23 14.57915 14.57915 14.57915