New census estimates show that while a growing number of Americans surf the Web, some states still lag behind in Internet adoption.

About 71 percent of U.S. households were connected to the Internet in 2010, according to Current Population Survey estimates released this week. That’s up from 61.7 percent in 2007, with the rate steadily climbing since the first homes plugged in during the 1990s.

But strong divides in Internet access remain, with adoption rates varying widely among different regions and demographic groups.

In some rural areas, Internet providers offer limited coverage or slow connection speeds. Many low income Americans also opt not to purchase Internet service, citing cost concerns.

Data indicates southern states have the nation's lowest household adoption rates.

New Mexico recorded a household adoption rate of 64.1 percent – the lowest of any state, likely explained in part by its high Hispanic and American Indian population, groups typically less likely to connect to the Internet. Mississippi and Arkansas reported the next-lowest adoption rates for residents age 3 and up.

By comparison, an estimated 86.2 percent of New Hampshire residents had household Internet access, the highest share in the 2010 survey.

The following chart illustrates the steady increase in Internet adoption, showing the percentage of total U.S. households with access since 1997:

The Census Bureau published the above yearly totals from survey results, but noted the wording of some questions varies from year to year. It's also worth noting that Americans without home access may instead use the Internet from work or school.

Many states recorded a significant boost in Internet access in recent years. Idaho led the way, with 80 percent of residents living in households with access, up from less than 62 percent in 2007. The state's increase was followed by Arizona, West Virginia and Kansas.

Household access jumped in all 50 states over the three-year period, although Indiana’s rate of 66.8 percent changed little from 2007.

The survey results did not distinguish among Internet connection types for state adoption percentages.

National data is broken down further, showing nearly 48 percent of Americans with home Internet access used cable line connections. Another 34.6 percent connected via slower DSL, while 4 percent were still limited to dial up.

It’s no surprise that less-educated individuals are far less likely to have their homes wired. Only 43 percent of those age 25 and older with less than a high school education and 66 percent who graduated high school but did not attend college had access at home, compared to nearly 91 percent holding at least a bachelor’s degree, according to survey data.

Household Internet adoption also varies across race and ethnicity: About 63 percent of Hispanics and blacks lived in households with access, compared to 81 percent for non-Hispanic whites and nearly 87 percent for Asians.