Washington ? The economy’s 5.7 percent growth last quarter — the fastest pace since 2003 — was a step toward shrinking the nation’s 10 percent unemployment rate.

There’s just one problem: Growth would have to equal 5 percent for all of 2010 just to lower the average jobless rate for the year by 1 percentage point.

And economists don’t think that’s possible.

Most analysts say economic activity will slow to 2.5 percent or 3 percent growth for the current quarter as the benefits fade from government stimulus efforts and from companies drawing down less of their stockpiles.

That’s why the Federal Reserve and outside economists think it will take until around the middle of the decade to lower the double-digit jobless rate to a more normal 5 percent or 6 percent.