What is the latest update on this Router?

Back in Dec 2016, I received an e-mail from Netgear with a link to a new Security Update for my R8000 Router.  I was not able to complete the update until now.  The link on the e-mail was for update: R8000-V1.0.3.26_1.1.18.chk.  When I loged into my Router, I found that it was telling me there was an update to be completed.  I completed the update that the Router informed me of.  The update that the router told me of is VI.0.3.36_1.1.25   When I completed the update, I noticed that the update requested via e-mail in Dec. 2016 is different than the update that the rounter told me to do.  Which one is the most updated update?  Should I do the Dec. 2016 update as well? Perhaps these to two entirely different types of updates.  Not sure.   I fear that I maybe going backwords if I do the security update now.  Perhaps the only update I need to do is the V1.0.3.361.1.25  that the router told me to do?  Can anyone out there point me in the right direction?  Thanks for your time with this!!