King County Elections credits prepaid postage services for the highest voter turnout in the county since the 2004 election.

Voter turnout in King County was the highest primary participation since 2004 thanks to prepaid postage stamps.

Before the 2018 Primary Election, King County Elections predicted turnout would reach 40 percent. Washington Secretary of State Kim Wyman believed the U.S. Senate race would help contribute to high numbers.

Prepaid postage stamps pushed voter turnout over 43 percent, according to King County Elections.

Voter turnout in the 2018 Primary Election was the highest since the 2004 primary.

Prepaid postage will be available again during the November General Election.