When looking at the trend, the value displayed is the most recent value. The trend comparison coloring and icon are calculated using the previous 4-10 measurement periods (depending on how many are available). So, if the current value for one location is 15% but has been increasing significantly (when increasing means to worsen), the icon will display a dark red upward arrow. If the other location has a value of 15% but has been decreasing not significantly over the last 4 measurement periods, the icon will display a light green downward arrow.