SQL SUM and Average Sale by Years
<p>I have a table where monthly sales are recorded. See image for a sample of the table.<a href="https://i.stack.imgur.com/HI7oA.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/HI7oA.jpg" alt="enter image description here"></a></p>

<p>So this data is partial, I have months 1-12 for every year since 2000. What I would normally do is query total sales for any one year like this:</p>

<pre><code>SELECT SUM(total_sales) as TotalSalesYear FROM sales_report WHERE year =  '2008'
</code></pre>

<p>What I want to do here is determine the highest year in sales and the average sales per year since 2000. So I need to do a SUM per year, and determine which year is the highest. Then, once I have the SUM for each year, I can come with an average of sales per year. </p>

<p>I'm just not sure how to query this.</p>

<p>Thank you.</p>