Q:

Google Sheets - Include a Comparison Trend Line

I am using google sheets to record sales data and have a separate worksheet for each calendar year. 
For each calendar year I include a couple of charts which illustrate things like track dollar value of sales per week and I've included a trendline. 
Now we've ticked over to a new calendar year, I'd like to include the trendline from last year's dollar value chart into this year's chart, so I can see how the trends compare. 
I don't really want to include the week by week data in the chart (it will look messy & I don't need that level of detail) - is there a way I can just include the trend line? 

A:

I have 'solved' this by pulling in the previous year's data, including the trend line in the series & then setting the colour for the series to none.  That way the trendline appears but the individual data points don't. 
I suspect this is the right way to do this but I'd be interested to hear of any other approaches.