How to Add / Download Outlook 2013

I purchased Office Pro 2013 a number of years ago and did not install Outlook, since we were using gmail-based email at the time with the company for whom I am a contract employee. Now we switched to everything Microsoft, and we have been given access to Office 365. I don't really want to overwrite all of my 2013 apps on my computer with the 2016 version which I won't really own, but will only have access to as long as I contract with the company providing it, but I would like to use just Outlook 2016 as a downloaded app. The company provides an all or nothing download of the 2016 Office apps, and I just want Outlook. I tried to download just Outlook 2016 but it would not install on my computer. I thought maybe if I added the 2013 version I could update it to 2016 (to which I have permission). Any ideas how I can accomplish this so I can use Outlook 2016 but not overwrite all of my currently installed 2013 apps? I need this just for mail merge, since (unlike gmail), I cannot do mail merge using the online version of Outlook.

Thanks in advance.