How to make a line chart with points from different tables?

[Gerbil]

I am trying to make a line chart of averages from the past 5 years, something like this:

Each point represents an average of all the datapoints for that year. However, I only have datapoints for the past two years (2023 and 2022). But I have historical information on what the values are for the previous years, from 2018 to 2021. So it's a separate table with static values. How do I create a line chart with a single line connecting all the averages from 2018 to 2023?

[Trevor_G · Accepted solution]

You can (and should) utilize a 'Date Table' for this. 

The two tables are connected through the common date table.

The x axis of your chart is this date table. 

Here is an article on creating and using a date table: 

https://learn.microsoft.com/en-us/power-bi/guidance/model-date-tables 

Once this is setup and connected, you can use a measure to combine both values into a single line. 

Here are the results: 

Here is the measure to combine them into one line: 

Here is the data model (using the 'Date Table' as the common connection: 

Here is a sample of the Date Table (done in excel): 

Here is the sample data (one data point for historical, and multiple for data points for 2022-2023):

Let me know if this works for you.