Inflation has come down from its historic highs, though not far enough to stop plaguing the economy just yet. That’s the takeaway from data released yesterday. First, the good news: Prices rose at their slowest pace in nearly two years, having climbed 5 percent in the 12 months that ended in March. The increase is still higher than the 2 percent annual rate that policymakers seek to keep the economy humming — but is down from a peak of 9 percent last summer. The bad news is that other measures — particularly indicators that exclude food and energy prices, which are known as core inflation — tell a more mixed story.