The National Insurance Crime Bureau (NICB) found adisturbing trend — an increasing number of thefts of vehicles withthe keys left inside. While overall vehicle thefts aredeclining, vehicles stolen with keys left inside are on therise. There were 126,603 vehicle thefts with keys reportedstolen in the United State between January 1, 2012 and December 31,2014.

Theft scenarios include opportunistic theft while a vehicle isbeing warmed up in the winter with keys in the ignition andinstances where thieves simply drove off because owners left keysin the vehicle console.

Older models stolen more

The report data suggests that older models may be more inclinedto be stolen this way, especially during the colder months, due tothe keys remaining in the ignition while being warmed up. Newermodel vehicles can be remote started without the need to keep thekeys in the ignition, making these vehicle less desirablefor opportunistic thieves.

[Related: You're the prime suspect if your car isstolen]

The reasons that people leave keys in their vehicles arenumerous, but none of them is worth the hassle of having your carstolen. Leaving your vehicle running while you run into a store fora quick cup of coffee or to warm it up before a chilly wintercommute might make sense to you, but it creates a perfect momentfor a car thief.

Looking at day-of-week data, Saturday saw the most thefts withkeys (19,147) followed by Friday (18,719) and Monday(18,647).

Out of the 126,603 vehicle thefts with keys, 9% were unrecoveredas of December 31, 2014. By state, Texas had the most unrecoveredvehicle thefts with keys with 1,036. California came in second with998 unrecovered thefts and Michigan was third with 990 unrecoveredthefts with keys.

As a whole, the top 10 theft states represent 59% of the vehiclethefts with keys. Keep reading to find out which states have thehighest vehicle thefts when the keys have been leftinside.

Rush hour traffic on I-25 looking towards downtown Denver,Colo. (Paul Gana / Shutterstock.com)

10. Colorado - 3,968 vehicle thefts

Traffic near downtown Atlanta, Ga. (Sean Pavone /Shutterstock.com)

9. Georgia - 4,102 vehicle thefts

The entrance to Holland Tunnel on June 14, 2014 in NewJersey. The Holland Tunnel is a highway tunnel under the HudsonRiver connecting Manhattan in New York City with Jersey City.(stockelements / Shutterstock.com)

8. New Jersey - 4,140 vehicles

Highway I-94 heading into Chicago, Ill. (Rudy Balasko /Shutterstock.com)

7. Illinois - 4,646 vehicle thefts

Traffic at sunset in Las Vegas, Nev.(Shutterstock.com)

6. Nevada - 6,448 vehicle thefts

Vehicles driving along the highway toward downtownCincinnati, Ohio. (Anne Kitzman / Shutterstock.com)

5. Ohio - 7,452 vehicle thefts

Exit to Chrysler headquarters and technology center inAuburn Hills, Mich. (alisafarov / Shutterstock.com)

4. Michigan - 7,726 vehicle thefts

Morning rush hour traffic in Miami, Fla. (Jonathan G /Shutterstock.com)

3. Florida - 7,868

Traffic in Austin, Texas. (CristinaMuraca /Shutterstock.com)

2. Texas - 8,796 vehicle thefts

Heavy traffic on the Golden Gate Bridge connecting SanFrancisco to Marin County, Calif. (Frontpage /Shutterstock.com)

1. California - 19,597 vehicle thefts

[Related: Hide your Hondas! The 10 most-stolen vehicles of2013]