The latest one year California population figures have been published (through 1 July, 2015). Some trends and facts are worth noting.
http://www.sandiegouniontribune.com/news/2015/dec/16/californias-population-grows-to-nearly-391-million/
California’s population is now about 39,100,000 million, an increase of 350,000 people — about a 0.9% increase for the 12 months.
The number of births was 507,000. We peaked at about 612,000 births in 1990, and have been gradually trending downward ever since — a trend all the more notable given that our state population was a tad under 30,000,000 in 1990.
http://www.dof.ca.gov/research/demographic/reports/projections/births/documents/2014BirthProj-Final.xlsx
The number of deaths (all ages) in that time period totaled 245,000. Given that the CA deaths in 2005 totaled 236,220, it appears that, even with an aging population, our death rate has slowed (thank you, modern medicine and less smoking!), which, considering our declining birth rate, actually is the major component in our population increase for this time frame.
https://www.cdph.ca.gov/data/statistics/Documents/VSC-2005-0501.pdf
Total immigration (legal and illegal) during this 12 month period was about 145,000 — responsible for about 0.38% of our population increase.
Perhaps most interesting is our CA net domestic migration — the movement between states. Contrary to what most think, since 1991 our net domestic migration pattern has reversed — with more people leaving CA annually for other states than are coming to CA. In this latest 12 month period, we lost a NET 61,000 to other states. I say again — NET. Since 1991 California has lost an astonishing 3.8 million people in net domestic migration to other states.
http://riderrants.blogspot.com/2015/04/were-california-real-estate-prices.html