I've never seen it before, but it appears to be inflation notation. It's a subscript on prices, so the year is the original year of the price, and the cost above it is the inflation-adjusted equivalent in present-day dollars.
I've actually been thinking of moving to Atlanta recently. I live in Portland OR right now, so the sprawl of Atlanta scares me, but I've heard there are good walkable pockets of it.
I walk my dog 2 hours a day; are there places where the sidewalk density is high enough and the busy road density low enough that I could do that and have some route optionality so I'm not just doing the same walk all the time?
Yes. I was at Puppet (nee Puppet Labs) for four years, one of the larger Clojure shops to my knowledge (not that I've been keeping close tabs on who's picked it up recently).
I switched jobs and language choice was not my #1 criterion. A very interesting opportunity that aligned well with my values (and paid better to boot), but was in a completely different tech stack (Python DS ecosystem, with some Scala). I love the language, think it's wonderfully concise yet expressive way to think about code, runs on a great platform for the web, and is a great fit for when team size exceeds codebase size (though not so much the other way around). All my fun software projects are still in Clojure or Clojurescript; I just wrote some today to scrape doggy listings.
In my experience -- I was a professional Clojure developer for 6 years (until 2018), and hung out in the #clojure IRC channel on freenode a lot between 2011 and 2014 -- the Clojure community tends to be very experienced. Clojure is not many people's first language, but tends to be a language you find your way to after dissatisfaction with other languages, or exposure to other lisps.
I'm sure you can find crappy or charlatan Clojure devs, but I was generally impressed with the Clojure devs I met in #clojure or at the cons. Overall I found the community to have high levels of both knowledge/experience and patience in explaining things thoroughly and precisely to people who were asking questions.