http://www.sltrib.com/sltrib/lifestyle/49821718-80/witnesses-god-bible-utah.html.csp?page=1
"That particular outreach began in earnest after the 2002 Winter Olympics and now has taken off. Today, Witnesses have 34 Spanish-speaking congregations in Utah (compared with 38 English-speaking ones)."
That makes sense, its been stated on here often enough that if there really is any real growth its coming from recent immigrant populations or in non-westernized foreign lands.