One of the recurring stories of election season is the questions raised by critics about the validity of Oregon's vote-by-mail system, a voting method that President Donald Trump bashed earlier this year in attacks that his followers have amplified ever since.

Here's what the LFO found:

"Between the years 2000 and 2019, Oregonians cast approximately 60.9 million ballots in statewide and special elections. The Oregon Department of Justice estimates that the Criminal Justice Division (and the Civil Enforcement Division) obtained 38 criminal convictions relating to voter fraud during that period," the LFO report says.

"The division obtained 38 criminal convictions for voter fraud out of the 60.9 million ballots in Oregon elections cast over a 19-year period. That amounts to a rate of 0.0000006%. These figures demonstrate that voter fraud is exceedingly rare in Oregon." Voter fraud is also exceedingly rare across the country, LFO noted: "In June 2020, the Heritage Foundation reviewed all voter fraud cases it could find over a 36-year period. Heritage found 1,285 cases of voter fraud out of more than 1.8 billion ballots cast in all 50 states from 1982 to 2018. That amounts to a rate of 0.0000007%."

There has been an uptick in convictions in Oregon since 2016, as it and other states communicate more about people who cross state lines and may have voted in more than one place.

"The most prevalent forms of voter fraud, according to [Oregon DOJ], are duplicate voting (e.g., a person who votes in more than one state in the same election) and ballot forgery (e.g., a member of a household who fills out the ballots of other household members and fraudulently signs their names)," the report says.

"There are numerous processes built into Oregon's vote-by-mail system to ensure integrity, including unique barcodes to track ballots, signature verification to prove voters' identities, and election security plans filed by county elections offices. Vote by mail also leaves a paper trail that can be audited. In fact, two academic studies have concluded that the election results in vote-by-mail elections are generally more accurate than the election results in polling-place elections."

Voters continue to return ballots for the Nov. 3 election at a rapid rate: As of 1 pm  on Oct. 19, 13.26% of Multnomah County ballots had already been returned, a pace far ahead of 2016. To find the official ballot drop site nearest you, click here.