Employers added a half-million fewer jobs in 2018 and early 2019 than previously reported, the Labor Department said Wednesday.

The revisions, which are preliminary, are part of an annual process in which survey-based estimates are brought into alignment with more definitive data from state unemployment insurance records. Wednesday’s revision covers the period through March; final updates, which will include the rest of 2019, will be released in February.

The revisions don’t change the overall picture of a healthy job market. But they do mean that 2018, which had ranked among the strongest years of job growth in the decade-long recovery, was weaker than previously believed. After the revision, hiring probably averaged under 200,000 jobs per month last year, down from the 223,000 initially reported and only modestly better than the 179,000 monthly jobs added in 2017.