condition mean min max ZT0-3 11.981475 11.855599999999999 12.10735 ZT4-7 13.80285 13.80285 13.80285 ZT8-11 14.850950000000001 14.850950000000001 14.850950000000001 ZT12-15 0 0 0 ZT16-19 15.8443 15.8443 15.8443 ZT20-23 15.672450000000001 15.672450000000001 15.672450000000001