SALEM (AP) - The rich got richer faster than anybody else in Oregon over the last two decades, according to a report issued this week by two left-leaning groups.

The income of the richest20 percent of Oregon families grew by 59 percent between the early 1980's and the early 2000s, according to the Center on Budget and Policy Priorities and the Economic Policy Institute - more than double the growth rate of other segments.

In that same two decade span, the middle 20 percent saw their incomes grow by 28 percent and the income of the poorest20 percent rose by 19 percent, according to the study.

Oregon was one of 38 states where the incomes of high-income families grew faster than the incomes of low-income families.

Oregon stood out in one regard: it had one of the country's widest income gaps between the richest and the middle 20 percent, the study said.  Income growth was 57  percent for the top 20 percent and 21 percent for the middle income group, according to the study's data, giving Oregon the 11th largest growth in income inequality between these two income classes.

Michael Leachman, a policy analyst with the Silverton-based Oregon Center for Public Policy, said Oregon's economic transformation helps explain that pattern. In the early 1980's, lumber mills played a much bigger part of the state's manufacturing-based economy providing far more solidly middle income jobs with the prospects for income growth over time.

Those jobs have vanished by the thousands and Oregon has become more reliant on service industries and high-tech companies that don't offer the same number of well-paying jobs as wood-products businesses did in their heyday, he said.

The study was based on Census income data, which was adjusted to account for inflation, the impact of federal taxes, and the cash value of food stamps, subsidized school lunches and housing vouchers. Income from capital gains also was included.

The findings echo the results of a 2004 analysis by the Oregon Employment Department, which fond that between 1990 and 2003, wage growth for median earners did not keep pace with either the poorest or the richest wage earners.

"People in the middle income brackets have been squeezed a bit over time," said  Art Ayre, an economist with the Oregon Employment Department.