Delta Lambda Phi (ΔΛΦ) is an international social fraternity for gay, bisexual, transgender and progressive men. It offers a social environment and structure similar to other Greek-model college fraternities. The fraternity was founded on October 15, 1986, by Vernon L. Strickland III in Washington, D.C.: becoming the first national social fraternity for gay, bisexual, and straight progressive men. The full, corporate name of the fraternity is Delta Lambda Phi Social Fraternity, but it is commonly referred to as "DLP" by its members. As of 2007, DLP was one of the fastest-growing fraternities in the United States.
Given this reference text about Delta Lambda Phi, during which years was the DLP fraternity not the fastest growing fraternity in the US?
Between 1986 and 2007, DLP was available, but not the fastest growing fraternity.