By THÉRÈSE MARGOLIS When Mexico first began importing cherries from the northwestern U.S. states of Washington, Oregon, Idaho, Utah and Montana 15 years ago, the initial sales were relatively small, barely 6,000 cartons in 2004. But as Mexico’s appreciation of the fleshy little cerises increased, so did the demand for the fruits. In 2018, Mexico imported an unprecedented 200,000 crates