BOSTON – Massachusetts only gained 9,100 jobs, not the 40,700 previously reported, in the 2011 calendar year, the Mass. Executive Office of Labor and Workforce Development said in March.

The revised figures equaled an employment-growth rate of 0.3 percent from December 2010 to December 2011. Under the previously reported figures, the rate sat at 1.3 percent.

The change had “significant” implications for the Current Economic Index of MassBenchmarks, a journal published by the University of Massachusetts’ Donahue Institute’s Economic and Public Policy Research, through a partnership with the Federal Reserve Bank of Boston. The state’s economic condition last year is not yet “well-understood,” MassBenchmarks said.

“[It] is a stark reminder of how much our understanding of the state economy relies on these official data sources and reminds us that an analysis is only as good as the data upon which it is based,” the journal said in a statement.

MassBenchmarks estimated real gross state product in Massachusetts grew 1.8 percent, as compared to 1.6 percent for the U.S. •