(Adds U.S. Census data on Puerto Rico)
NEW YORK, Sept 29 (Reuters) - Puerto Rico's economic activity has slumped to its lowest level in two decades, according to an index released by the commonwealth's Government Development Bank (GDB) on Monday.
The bank's economic activity index fell 1.1 percent in August year-over-year, putting the headline index at the lowest level since 1994. The index also showed a sharp drop in electric power generation and cement sales.
Electric power generation for August fell 4.1 percent while cement sales slumped 22.4 percent. A turnaround expert was recently appointed at the island's power authority PREPA, whose debt troubles are indicative of the wider stress threatening the U.S. territory.
However, the index showed that private employment grew for the sixth month, up 0.4 percent from a year earlier.
Puerto Rico has been in or near recession for eight years. The rate of decline in the index has slowed from previous years but they are decline will be a concern to policymkers trying to reverse the fortunes of Puerto Rico's economy.
The publication of the index comes shortly after the U.S. Census released data on Puerto Rico showing household income fell by 2.3 percent in 2013, a sharper decline than posted by any U.S. state. Median household income was $19,183 in 2013. (Reporting by Megan Davies; Editing by Chizu Nomiyama and W Simon)