30 years of gun sales, or graphics showing gun control effort's unintended consequences
A couple of months ago, when I had some free time, I dipped a toe into some of the BATFE's sales data on guns. Today, having lots of free time (avoiding the shopping frenzy and distracting myself from some personal issues) I went deeper into the ATF's data and crunched some numbers. I subtracted exports and added imports, and got a slightly newer version of the report (data goes to 2015, not 2013).
There are download links for the author's spreadsheet (data and graphs) in both .xls and .ods forms.
I downloaded the .ods and it loaded perfectly into LibreOffice calc.