Its report pegged U.S. Mormon growth at 45.5 percent, jumping from 4,224,026 in 2000 to 6,144,582 in 2010. The 2000 figure, though, was much lower than the 5,208,827 listed in the LDS Church's almanac. If researchers had been given that figure, the percentage of growth would have been considerably smaller, closer to 18 percent.