Bone mineral density and cola consumption has been recorded for a sample of patients. Let x represent the number of colas consumed per week and y the bone mineral density in grams per cubic centimeter. Assume the data is normally distributed. A regression equation for the following data is =0.8893-0.0031x. Which is the best interpretation of the slope coefficient?

x	y
1	0.883
2	0.8734
3	0.8898
4	0.8852
5	0.8816
6	0.863
7	0.8634
8	0.8648
9	0.8552
10	0.8546
11	0.862