The author made so many changes and updates that, after reading the article, I have no idea what compares with what.
The AP currently lists total WI votes for the Presidential race at 3,289,474. The WI gov elections site voter turnout spreadsheet estimates voting age population at 4,536,417.
3,289,474 / 4,536,417 = 0.725 ==
72.5% turnout for 2020The WI data for 2016, by comparison, put total votes in the general election at 3,004,051 from a voting age population of 4,461,068.
3,004,051 / 4,461,068 = 0.673 ==
67.3% turnout for 2016