California is the state most obsessed with unidentified flying objects (UFOs) and reported more sightings of UFOs from 2001 to 2015, according to an in-depth analysis of the UFO phenomenon in the United States.

"UFO-Happy" California is followed by Florida, Texas, Washington, Pennsylvania, New York, Arizona, Illinois, Michigan and Ohio.

These intriguing snippets of data are to be found in the "UFO Sightings Desk Reference: United States of America 2001-2015." Cheryl Costa, author of this work and a popular UFO writer, described her work as a deeper look into UFO sightings.

Costa is a retired aerospace security engineer and a military veteran with a lifelong interest in UFOs. From 1998 to 2001, she hosted "The X Factor" talk radio program in Washington, D.C. covering UFOs and many other paranormal topics. In 2013, she began writing New York Skies, a weekly newspaper blog for SyracuseNewTimes.com.

Costa's UFO Sightings Desk Reference, which comes to 374 pages, was based on data found in The National UFO Reporting Center (NUFORC) and the Mutual UFO Network (MUFON) from 2001 to 2015.

Costa revealed that California is number one among UFO-crazy states with its almost 16,000 sightings. That number accounts for 13 percent of all reported sightings in the U.S. over this 15-year time span.

Los Angeles County topped California's UFO sighting with 3,200 sightings. That number's larger than the number of sightings in 40 states in the Union.

Costa said there were more than 120,000 UFO sightings in the U.S. from 2001-2015. She also noticed seasonal patterns of sightings with numbers climbing during the spring and summer.

Costa used both databases every week looking for UFO sightings in New York for her column in the weekly Syracuse New Times. The strong response to this data from the reading public convinced her to expand the report's reach to include every state in country.