condition mean min max ZT0-3 10.078726 10.078726 10.078726 ZT4-7 10.988578 10.988578 10.988578 ZT8-11 12.08364 12.08364 12.08364 ZT12-15 12.432534 12.432534 12.432534 ZT16-19 13.0236695 13.0236695 13.0236695 ZT20-23 14.1982745 14.1982745 14.1982745