Indeed, prior to 2015 it had double digit inflation, thought this has declined to just under 3% per year and will continue to fall.
Morever, some estimates suggest up to 1/3 of all BTC are unspendable (lost keys, malformed txns, minute dust UTXOs, etc) so the deflationary spiral could have already been under way.
2015: Block reward: 25 btc * 6 blocks per hour * 24 hrs* ~250 euro = 900.000 euro worth of daily mined supply
2017: 12.5 btc * 6 blocks * 24 * ~2000 euro = 3.6 Million