King County’s annual census of unsheltered residents offers glimmers of hope, but the data isn’t reliable enough to declare a breakthrough in the region’s ongoing effort to end homelessness.

This highlights the need for better data to gauge progress and remaining challenges. The public needs to know how its huge investments in homelessness are performing, and whether the gains are proportionate with spending increases.

Statewide, this year’s point-in-time counts found a 9% decrease in the unsheltered homeless population and a 2.9% increase in the sheltered homeless population. The total population was estimated to be 21,621, down from 22,304 last year, according to the state Department of Commerce tally.

King County is estimated to have had 11,199 people experiencing homelessness during its January count, down 8% from 12,112 last year. Most striking was a 38% drop in chronically homeless individuals. It found 10% fewer homeless veterans and 36% fewer people living in vehicles.

Also encouraging was that the number of families experiencing homelessness declined for the third consecutive year, and 97% of them are sheltered, although the survey warns that it’s hard to be sure because locating such families to count is difficult.

Volunteers and a professional surveying firm also found a 28% drop in homeless youth, unaccompanied by adults, and young adults. The drop was greater for unsheltered children under 18 — the census found 55 this year, down from 138 in 2018. If accurate, this is a positive trend. But there should be zero children living alone on the streets.

Declines in youth homelessness reflect concerted focus by nonprofits, businesses and others, plus a surge of nearly $10 million of state and federal spending targeting homeless children.

The annual count is a rudimentary tool but suggests some strategies are working and “should make us want to double down” on them, said Casey Trupin, director of youth homelessness at a Seattle foundation started by Microsoft veterans Jeff and Tricia Raikes.

The Raikes Foundation and partners, such as Pearl Jam’s Home Shows initiative, are exploring ways to intervene faster with homeless youth and earlier with those at risk of becoming homeless. That includes work in schools and case management in the juvenile justice system, to arrange housing and reduce the inflow of people into homelessness.

Such philanthropy is extraordinary and can’t be counted on forever. So the idea is to develop approaches and models that are effective and can be replicated elsewhere, Trupin said.

“We can do some of the risk-taking here because of the philanthropy and show the return on investment in a way that other communities that don’t have the Pearl Jam, the Microsoft, the Starbucks” cannot, he said. “Then public funders can feel more confident about investing in what we’ve done here with less risk.”

That commitment to innovation and long-term solutions should inform a new statewide strategy for homelessness being developed by the state Commerce Department. A legislative audit last month said the new plan must do a better job of identifying how statewide actions and performance measures are working to reduce homelessness.

Commerce Director Lisa Brown, a former professor and state Senate majority leader appointed in January, is well-prepared to lead this effort and raise the agency’s profile in this statewide crisis.

As curator of the state’s homeless population data, Brown should also advance efforts to produce more and better information about the scope of the problem, remaining challenges and where there’s progress to celebrate.