If you look at two sets of data often used to track pricing trends for auto insurance in America over time, you would see that the price of insuring a car in the United States dropped by a total of 6.75 percent between 2004 and 2008, and it also rose by a total of 3.4 percent during the same period.

But just how could two reputable sources of information – the National Association of Insurance Commissioners (NAIC) and the Bureau of Labor Statistics (BLS) – report that the average cost both went up and down at the same time?

“When you look at the BLS and NAIC numbers, you need to take into consideration what each is really measuring,” says Cesar Diaz, CEO of auto insurance quote comparison site onlineautoinsurance.com. “At their cores, the NAIC and BLS statistics are tracking two different things, and the difference between them has important implications for consumers.”

Learning the crucial difference between price and expenditure

To generate its data, the BLS – which reported the 3.4 percent increase – takes sample driver profiles from all over America, gets quotes from real companies for those profiles and then tracks changes in their prices over time.

Since they are only samples, the drivers that they theoretically insure cannot adjust deductibles, change financial protection levels, improve their driving records or conduct a car insurance comparison to find a better deal – all of which may help reduce the policyholder’s economic burden. Rather, the BLS set the policy and driver details in stone when they chose the profiles, and it only adjusts the premiums in response to vehicle upgrades and changes in insurers’ pricing structures.

If the insurers suffer huge losses and have to adjust their pricing formulas, premiums simply go up. The holders of those policies cannot react as those in the real world can.

The NAIC – which reported the 6.75 percent decrease – on the other hand, looks at the total premiums that policyholders pay for liability, comp and collision coverage in each state and then divides that by the total number of insured drivers who purchased them. This process in effect gives a view of the actual expenditures that policyholders in each state have.

“Statistics show that, on average, when consumers keep the same policy, prices are likely to go up after a while,” Diaz says. “But consumers can offset the increases by making smart choices when it comes to coverage options.”

How to offset gradual price increases

There are plenty of websites and consumer guides devoted to showing consumers how to slash premiums, but here are a couple of the more reliable tactics:

*Adjust your comprehensive and collision deductibles. For those who are struggling to pay the cost of insuring their own cars against physical damage, you may want to consider raising deductibles or eliminating this optional coverage on older cars. The Insurance Information Institute says raising deductibles can amount to savings of anywhere between 15 and 40 percent. Doing so may result in greater out-of-pocket expenses in the event of a claim, though.

*Driving less? Ask about low-mileage discounts. According to the latest report from the Federal Highway Administration, the number of miles that Americans drive in the month of April was at its lowest point this year since 2003. Motorists who put in fewer miles behind the wheel statistically are at a lower risk of getting into an accident, and insurers may reward them with significant price breaks.

*Shop around. While the drivers in the BLS statistics are essentially chained to their insurers, you are not. Nearly 8,000 domestic insurers were selling coverage in 2009, according to the NAIC, with a significant chunk of them providing financial protection for vehicles. That’s a lot of competition, and all of those companies are trying to come up with new incentives for you to get a policy through them. You can easily find cheap auto insurance through quote-comparison sites that will help you efficiently evaluate your options and track down the best deals for your individual driver profile.