linking custom post types

I’m trying to create an events site. the site will have 1 event a year. I would like the site to load, for example, https://www.eventsite.com/2015 and this would be the home page to load the 2015 event. I have created a custom post type for event, speakers, venue, and sponsors.

The problem i’m having is tying the CPTs together. Ie when someone is looking at the 2015 event they only see the speakers, venue and sponsors for that event.

https://www.eventsite.com/2015/speakers would load the custom post types archive page for speakers in the 2015 event.

https://www.eventsite.com/2016/speakers would load the custom post types archive page for speakers in the 2016 event

https://www.eventsite.com/2015/speakers/jon-walker would load the custom post type single page for the speaker jon walker in the 2015 event.

https://www.eventsite.com/2016/speakers/jon-walker would load the custom post type single page for the speaker jon walker in the 2016 event. who may or may not be the same person so it would have to be a different speaker post.