Los Angeles County's population increased by approximately 37,000 in 2011, according to figures released by the California Department of Finance this week.
The estimates are compiled using driver license change of address forms, public school enrollment and tax returns, according to the department press release.
Population totals were released for specific incorporated cities and towns throughout the state, but as Altadena is not incorporated, no estimated population change was released. Unincorporated L.A. County areas as a whole grew by about 3,000 to 1,062,073, an increase of about 0.3 percent.
The county's updated population figure is 9,884,632, an increase of about 0.4 percent.
Altadena's population is likely to have remained stable: from 2000 to 2010, , according to census figures.
As a whole, California's population increased by about 250,000, a 0.7 percent increase.
To view more city, county, and state data visit the department website.