It really seems to be more like a ten-year cycle. It was miniumum around 1966, too. If it were an 11-year cycle, we would see the minimum around 2010.
Somewhere I remember seeing a collection of sunspot numbers and cycles that went back to when they first stated collecting them. Shortest cycle about 9 years and longest about 13.5 years. Since cycles can overlap, depending on who's tracking, 11 years seems to be the smooth number.
