According to Rasmussen Reports, Barack Obama’s approval ratings are dropping fast: Daily Presidential Approval Index.

The Rasmussen Reports daily Presidential Approval Index for Sunday shows that 36% of the nation’s voters now Strongly Approve of the way that Barack Obama is performing as President. Twenty-five percent (25%) Strongly Disapprove to give Obama a Presidential Approval Index rating of 11.

The Presidential Approval Index is calculated by subtracting the number who Strongly Disapprove from the number who Strongly Approve. It is updated daily at 9:30 a.m. Eastern (sign up for free daily e-mail update).

One week ago today, 44% Strongly Approved and 23% Strongly Disapproved to give Obama a Presidential Approval Index rating of 21.

In the first set of interviews conducted after inauguration day, 45% Strongly Approved of his performance while 16% Strongly Disapproved for a Presidential Approval Index rating of 29 (see trends).

Overall, 59% of voters say they at least somewhat approve of the President’s performance so far while 39% disapprove. Today’s results mark the first time that Obama’s overall rating has fallen below 60% as either President-elect or President.