Technically from 2008... You know before Obama was President. Check for yourself, it dropped to the low on December 16th, 2008.
The Great Recession was closer to a complete collapse than most people realize. We nearly fell into a liquidity trap, and needed not just low interest rates, but even quantitative easing to avoid deflation.
Deflation is not a problem now, but trump wants quantitive easing to gin up the economy. It causes inflation, which is a good thing to fight deflation, but again, no deflation.