Show the historical charts by clicking the chart icon that appears on the right of the 'Keyword' column when you hover over it.
From here, you may change the time-frame of the chart and show the ranking URLs for the keyword.
Fill in Rank Drop Gaps in Charts
When "Fill in Rank Drop Gaps in Charts" is enabled within your settings, this will fill in any gaps in your keyword chart to smoothen the progress line out.
To enable, click the 3-dots -> Project Settings -> Check "Fill in Rank Drops Gaps in Charts"
Not filled in:
As you can see from the screenshot, the gaps or the times that it fell out of the Top 100 position are filled in. This does not mean that your keyword ranked in the position that is showing. The chart only linked the gaps from the last time it ranked to the next time it ranked in the Top 100.
Inaccurate rank history
If the chart shows a rank that you think is inaccurate, we recommend following the steps below.
Export your Project history. You may export the history here.
Double-check the date(s) you think are inaccurate
If you confirmed with the history that the chart's report is not showing the correct rank, check your settings for "Fill in Rank Drop Gaps in Charts" if it is set to fill in or not.
If you are still seeing an inaccuracy, please contact us and we'll be more than glad to help you out.
While in the Historical Charts you can click on SERP History and see how your keyword ranked over time compared to your competitors.
If the keyword you are tracking has been previously tracked in Keyword.com by other accounts, you will have SERP history for the period before you added the keyword to your project, allowing you to see your keyword competitors performance over time.