Small business owners had a slightly worse outlook in March than in February, according to a monthly survey by the National Federation of Independent Businesses.

The NFIB’s Small Business Optimism Index, which surveyed 759 randomly sampled small business owners in the organization’s membership, fell 1.3 points to 89.5 in March. The index is calculated on owners’ expectations in several areas including sales, employment, credit, and inventory.

March’s index marks the first drop in optimism in three months — it had risen 1.9 points between February and March. It is just below the survey’s 44-year average of 90.7.

Despite the decline in optimism, owners planned to add an average of 0.19 workers per firm, the most the survey has seen in a year.

Twenty-three percent of small business owners said taxes were their biggest business problem, and 21 percent answered “red tape.” Only three percent of owners reported credit as a major business problem, a near record low, according to the survey.

The NFIB’s chief economist, Bill Dunkelberg, cited uncertainty the main cause for the drop in optimism. “Virtually no owners think the current period is a good time to expand, because they simply don’t know what the future holds.”

The NFIB has been a frequent critic of President Obama’s small business policy, heavily contributing to Republicans and opposing Democrats, according to research on from the Center for Responsive Politics.