Negative Correlation

Noun
1. a correlation in which large values of one variable are associated with small values of the other; the correlation coefficient is between 0 and -1
(synonym) indirect correlation
(hypernym) correlation, correlational statistics
(classification) statistics

The relationship between two variables is such that as one variable's values tend to increase, the other variable's values tend to decrease. This is represented by a negative correlation coefficient.
See also, Correlations - Introductory Overview.