condition mean min max ZT0-3 6.1554150000000005 5.65704 6.653790000000001 ZT4-7 6.74907 6.74907 6.74907 ZT8-11 6.725205000000001 6.725205000000001 6.725205000000001 ZT12-15 0 0 0 ZT16-19 8.98747 8.98747 8.98747 ZT20-23 8.586065 8.586065 8.586065