-3% or so in 2015, but of course I have lost a ton already in 2016 (I'm 100% in index funds, so whatever that ends up being). I've lost about $24k in my taxable accounts and about half that in my retirement accounts (because my retirements accounts are about 1/3 of my investments).
Of course I got my 2015 bonus on December 30 and funded all of it into the market that day. Quick way to lose several thousand dollars, that.
As I tell my spouse, though, we'll "make it back" eventually--though having such terrible timing is super annoying, because I put about $120k into the market right before (literally, two days before) the market took its big dive in 2015, and then I put another 50k or so in... a few days before the 2016 chaos hit. If we don't make it back, it's because the stock market literally never recovers from the 2015/2016 drop (including any further drop), which basically means the world will have ended, and we'll have much bigger problems than the performance of our investment portfolio.
That said, sure do wish I had put it all into a savings account instead.