Last year’s presidential campaigns focused huge percentages of their time and money on states where only about one-third of eligible voters lived, according to a new report released Thursday.

Ninety-nine percent of ad spending from the two major campaigns and 95 percent of their candidates’ appearances occurred in 14 battleground states, the report from Nonprofit VOTE and the United States Elections Project found. Just 35 percent of eligible voters lived in those states, while the remaining 147 million voters lived elsewhere.

A mere four battleground states ― Florida, North Carolina, Ohio and Pennsylvania ― saw 71 percent of the ad spending and 57 percent of the candidate appearances.

This disparity was driven ultimately by the Constitution, which requires presidential hopefuls to win in the Electoral College ― as President Donald Trump did ― whether or not they take the popular vote ― which he did not. After the election, some called for the elimination of the Electoral College.

The 14 states identified as battlegrounds were Arizona, Colorado, Florida, Georgia, Iowa, Maine, Michigan, Nevada, New Hampshire, North Carolina, Ohio, Pennsylvania, Virginia and Wisconsin. Trump won nine of those states.

Two of the groups that disproportionately lost out with the uneven allocation of campaign resources were Latinos and Asian Americans/Pacific Islanders. Seventy-five percent of Latinos and 81 percent of Asian Americans/Pacific Islanders did not reside in one of the 14 battleground states. Overall, just 35 percent of Latino voters and 42 percent of Asian Americans/Pacific Islanders said they had contact with a campaign, the report found. However, those in battleground states had levels of campaign contact that were 10 to 16 percentage points higher.

Among all eligible voters, 60.2 percent cast a ballot last year, up from 58.6 percent in 2012, the report said.