Philocrites, in two postings, announced the thirty-six greatest growing congregations, and rather plainly points out how few congregations make up the bulk of the UUA's net growth.
The problem with the lists is that it depends upon UUA data that seems to reset the clock at when a church is founded. But this includes a church being renamed or reconfigured, but not started from scratch. Fair being fair, I think a few of the thirty-six should be removed and some "honorable mentions" should be brought forward. After all, I want to know what churches are really growing because they may have lessons worth reproducing.
So, let's look at Chalice Unitarian Universalist Congregation of Poway, California. While the UUA database records it as being founded in 2000, it is in fact a merger of two pre-existing congregations: the Chalice Unitarian Universalist Church and the Inland North County Fellowship, of Rancho Bernando. (This is recorded online with the UUA Board of Trustees minutes of January 22-23, 2000.) A fair accounting would see what the 1993 memberships of both congregations were, and calculate the difference between that sum and its current membership. I doubt it would make the top group. Do recall this church in your prayers, though, as it was one affected by last year's fires.
The Atkinson Memorial Church, Oregon City, Oregon, is a bit trickier. Until recently, it was jointly a member with the National Association of Congregational Christian Churches, but has since droppped that membership. Perhaps part of its growth is due to accounting for members formerly accredited to the NACCC. A fair accouting would compare its current reported membership with its full membership in 1993.