(CNN) Voters who identify as independents are rarely actually independent -- and the ones who are tend to not care about politics, according to a new analysis by the Pew Research Center.

Independents are often seen as the best possibility for potential candidates to pick up votes outside their bases, but most independents actually "lean" toward one party or another, according to the analysis. Less than 10% of the population say they truly have no partisan lean.

In general, the number of Americans who consider themselves independents increased from 33% in 1994 to 38% in 2018.

Americans who identify as independents are more likely to lean toward the Democratic Party (17% of the total population) than toward the Republican Party (13% of the total population).

In 2018, just 7% of all Americans say they truly have no leaning toward either of the major parties. Those without a partisan lean -- true independents -- haven't increased as a share of the population, staying under or near 10% since Pew started tracking the question in 1994. Pew reports that those who do not lean toward a party are part of "a group that consistently expresses less interest in politics than partisan leaners" and "were less likely to say they had registered to vote and much less likely to say they voted."

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