CNN  — 

More than a third of registered voters – over 75 million Americans – have already voted with six days left until Election Day, an unprecedented shift driven by the coronavirus pandemic and interest in the presidential race.

As of Wednesday evening, about 36% of registered voters have already cast ballots ahead of November 3, according to a survey of election officials in all 50 states and Washington, DC, by CNN, Edison Research and Catalist.

The top three states with the highest percentage of registered voters who have already cast ballots are Montana, Washington state, Colorado and Oregon – all have extensive mail-in balloting this year.

Montana leads all states with about 56% of registered voters already having cast ballots. The state is allowing counties to conduct their elections entirely by mail if they choose.

Washington follows, where about 53% of registered voters have already cast ballots already returned, and Colorado and Oregon are just behind at 52% each.

In an additional 14 states, at least 40% of registered voters have also cast ballots. Among CNN’s most competitively ranked states – besides Colorado – North Carolina (roughly 50%), Georgia, Texas and Florida (all at 48%) are seeing the highest turnout as a share of registered voters so far.

New Hampshire (18%) and Pennsylvania (22%) are the key states that have seen the smallest share of voters cast ballots already. Both states are allowing any voter to vote by mail for the first time this year, but neither has a tradition of extensive pre-election voting.

Some states may have different rules for determining which voters are eligible to cast ballots for the general election, and many states also allow for same-day registration on Election Day. It’s not clear how much of the record-breaking early vote comes from people who would have voted on Election Day and how much represents additional turnout this year.

The 75.8 million ballots cast so far in the 2020 election also represents about 56% of the more than 136.5 million total ballots cast for president in 2016.

Twenty-five states and Washington, DC, have also crossed their halfway marks for total 2016 ballots cast, including 10 of the 16 key states – Texas, Georgia, North Carolina, Florida, Nevada, Arizona, Colorado, Wisconsin, Iowa and Maine.

Pre-Election Day voting is skyrocketing nationwide amid the ongoing coronavirus pandemic, and states are reporting record-breaking turnout as voters are energized to vote by mail or early in person before November.

On Sunday, the nation surpassed the 58.3 million total pre-election votes cast in 2016. Forty-two states and DC have now exceeded their pre-election voting levels from 2016.

Some data included is provided by Catalist, a company that provides data, analytics and other services to Democrats, academics and nonprofit issue-advocacy organizations.

This story has been updated to reflect voting data as of Wednesday evening.