SEATTLE » Gay weddings made up 17 percent of marriages in Washington this past year, the first year gay marriages were legal in the state, state officials reported Wednesday.

About 7,071 same-sex couples got married in Washington between December 6, 2012, and the most recent complete month of data, September 2013. There were 42,408 total marriages in the state during that time, according to the Washington State Department of Health.

So far, most of Washington state’s same-sex marriages, 62 percent, were between two women.

Washington is one of 15 states plus the District of Columbia where gay marriage is legal, but few have the kind of detailed data Washington released this week, in part because gay marriage is so new in most places.

According to the 2010 Census, there were about 152,335 same-sex married couples and 440,989 same-sex unmarried couples in the United States.

According to the Massachusetts Department of Public Health, during the first year and a half after gay marriage became legal, 8,181 same-sex couples got married. Between May 2004 and the end of 2012, 22,406 gay couples got married in Massachusetts.

Both Washington and Massachusetts warn that these numbers are close estimates, but not perfectly accurate, since gender information was not properly entered on every marriage certificate.

In California, the UCLA School of Law’s Williams Institute estimated 18,000 gay couples married in 2008 when same-sex marriage was legal for four and a-half months. Those numbers are not based on marriage license information because California, like many states, does not request gender information on license applications.

One of the main sponsors of the Washington state law that led to gay marriage said the wedding numbers were higher than he expected.

During the five years before Washington’s gay marriage law, when the state had what was affectionately called "everything but marriage," only 9,500 couples registered themselves as domestic partners, including about 950 who were not gay, said state Rep. Jamie Pedersen, D-Seattle.

"In terms of the uptake in marriages, that’s a remarkable number," he said.

Pedersen said he was also pleased to be proven right about a few others things: that gay marriage would drive tourism and that there was considerable interest in the institution among couples from across the state.

All but one of Washington’s 39 counties — Garfield County — reported same-sex marriages during the first 10 months of the law. The top five counties were King, Clark, Pierce, Snohomish and Thurston counties.

About a quarter of the gay couples who got married this past year in Washington were from another state. The biggest number, 524, came from Oregon. For 170 marriages, the couples live in Texas and 155 couples traveled from California to get married in Washington.

In only 6 percent of marriages for opposite-sex couples, both spouses were from another state.