Property tax assessments on homes in Detroit will be reduced this year 5 to 20 percent citywide, Mayor Mike Duggan announced Monday.

Darren A. Nichols reports in the Detroit News the new assessments could potentially mean tax relief for thousands of Detroit homeowners who have been overtaxed for years. A state agency is already looking into whether Detroit has overtaxed property owners through inflated assessments on homes.

The city used current assessments and actual home sales from Oct. 1, 2011, to Sept. 30, 2013. It found nearly the whole west side was overassessed by a minimum of 20 percent.

During the next three to five years, the city will conduct individual assessments of single-family homes for a more accurate evaluation, according to the Duggan administration.

The announcement follows a Detroit News analysis last year by Christine MacDonald of more than 4,000 appeal decisions from 2010-12 by a state board. In the first public examination of its kind, The News’ review revealed that Detroit was over-assessing homes by an average of 65 percent, leading to higher tax bills.

The series reviewed Michigan Tax Tribunal cases of Wayne County property owners appealing tax bills. The analysis found the administrative court reduced Detroit property values at a far higher rate than neighboring communities and nearly 50 percent more than the county average. The state subsequently said it would investigate.

McDonald reported Detroit’s tax rate of 67 mills for homes — the rate at which property taxes are levied — is among the highest in the state. And professionals who fight appeals said The News’ analysis makes a strong case that city assessments — and taxes — are off by wide margins.

They argue the cost to the city has been great: In two years alone, 10 percent of all Detroit properties have been foreclosed because of unpaid taxes.

Read more: The Detroit News