The percentage of ballots returned by Colorado voters has edged up to almost 15 percent, the Department of State reported Tuesday. The total now is 452,595.

All 3.09 million active voters received ballots by mail this year and must return them by mail or drop them off at vote centers by Election Day next Tuesday.

Republicans are continuing to return ballots in the greatest numbers. Some 42.2 percent of the returned ballots were from voters registered as Republicans, compared to 30.4 percent for Democrats and 26.3 percent from unaffiliated voters.

The percentage of returned ballots is below the statewide average in six major counties, Adams, Arapahoe, Boulder, Denver, El Paso and Pueblo. Denver has the lowest percentage of returned ballots at 9.8 percent.

The rate of ballot returns is running above the state average in Douglas, Jefferson, Larimer, Mesa and Weld counties. Republican-leaning Douglas County, which has four high-profile school board races, has 21.9 percent of ballots returned.

Turnout by party and county is expected to be a factor in the success or failure of Amendment 66, the proposed $950 million income tax increase for P-12 education.

One veteran political consultant told EdNews that voter turnout doesn’t look like it will be higher than in 2011, which could be a negative indicator for A66’s chances. “The Amendment 66 campaign isn’t changing the 2013 electorate much from what it was two years ago, nor mobilizing those 2012 Obama voters to turnout and vote in this year’s election, or at least not yet,” he said.

In 2011 about 1.07 million ballots were cast, some 50 percent of active voters. That election also featured a school-funding proposal, the lower-profile and unsuccessful Proposition 103.

See the list of ballot return information for all counties here. The department’s next update is scheduled Thursday.

The chart below gives the early voting stats for the state’s 11 largest counties as of Tuesday. Light blue shading indicates Democratic-leaning counties, light red GOP ones and lavender indicates counties where unaffiliated voters are the plurality group. The three right-hand columns show the percentage of voters by registration who’ve returned ballots.

Chart