As a default, Polkadot Tiger shows you the combined performance for all search terms the page was returned for within the testing period. This default chart is an average of all search terms combined so it gives you a good overview of performance but not exact data.
You do, however, have the option to see the results of your tests based on which search terms they were shown for.
Click on the dropdown list on the left, above the graph. You will see the list of keywords you specified earlier. Select the one you are interested in and the chart will show the performance for that particular search term.