The phrase “historically low unemployment” has become almost a cliché, losing its oomph through overuse by self-congratulatory leaders. Still, with joblessness in April at 3.4% (it rose slightly in May), it’s worth recognizing how unusually low the numbers have been. This spring, 15 states were at their lowest unemployment levels since 1976, and all but Nevada were at or below the 5% rate that economists say represents “full employment.” These lows have fueled the strong consumer spending and pay increases driving inflation. But recent history may explain why they don’t translate into greater optimism: Barely three years ago, 45 states hit record highs in unemployment, the result of pandemic-induced shutdowns whose disruptions still haunt us. So think of this graphic as an illustration of economic whiplash.