Bitcoin is not deflationary, regardless. It's asymptotically inflationary. It's only deflationary if people lose/misplace wallet files faster than the new currency is minted. In fact, BTC is much more inflationary that USD right now.
Bitcoins has seen 100%, 50%, and now 30% annual monetary inflation. Dollars have seen 300% M0 monetary inflation with the quantitative easing in 2008-2009. Currently this month, bitcoins are price inflating (currency devaluation) rapidly against the dollar (10% for the past week), but over the years, bitcoin has deflated 80% monthly against the dollar on average (doubled every ~50 days).