There are two types of comparisons that look at how the indicator is doing over time - the trend and the prior value.

**Prior Value**The prior value comparison looks only at how the indicator is doing compared to the previous measurement period. When available, we use confidence intervals to determine the change in the prior value. The prior value gauge is a triangle that points up or down based on the direction of the data. If the change is good, the triangle is green and if the change is bad, the triangle is red. If there is no change in the value, a blue equal sign will be displayed.

**Trend**The trend looks at how the indicator is doing over multiple time periods. We analyze up to 10 previous measurement periods (and at least 4) to determine if the value is going up significantly, not significantly, staying the same, decreasing significantly or decreasing not significantly. A solid color gauge means that the change is significant and an outlined gauge means there is a change but it is not significant. A red gauge represents a poor trend and a green gauge represents a positive trend. The blue gauge with an arrow means that going up or down is neither positive or negative and an equal sign means there is no change. To learn more about the different icons, visit the Gauge and Icon Overview page.

To learn more about how we calculate this rate, please visit the Mann-Kendall Test for Trend Overview.