Seven years after passage of the Plain Writing Act, the clarity of federal agency websites “is improving, albeit slowly,” according to an assessment by a firm that provides consulting services on clear communications.

It measured up to 100 pages of sites from 30 agencies for readability, use of passive voice, lengthy sentences and complexity of wording. It found “some improvement” overall in every measure except for use of long sentences. “This area is among the easiest to address and can lead to some of the biggest gains in clarity,” the VisibleThread company added.

Overall top rankings went to the National Archives and Records Administration, CDC, Community Oriented Policing Services, the Smithsonian and FAA.

Agencies that made notable improvements over 2016 were the National Cancer Institute, the SSA, Pension Benefit Guaranty Corporation, National Highway Transportation and Safety Administration, Health Resources and Services Administration, and DHS. Those gains were due mainly to improvements in readability and reduced use of complex language, it said.

Agencies seeing significant drops included BLS, U.S. Geological Survey, U.S. Mint, Transportation, and the HHS program support center–with no particular pattern in the declines.

At the bottom were Substance Abuse and Mental Health Services Administration, Natural Resources Conservation Service, Federal Highway Administration, FBI, and Federal Railroad Administration.