As the decade started, it was mostly vinyl; I got a CD player in 1986, but didn't have a ton of CDs yet. I'd make tapes for my car, because I didn't have a CD player in it.
As the decade ended, I had a CD player in the car, and had a 2 year old that could do damage to vinyl if left where he could find it. I also had a decade of collecting the shiny discs, and played vinyl less and less.
JcS