In-tank fuel filter -- how many hours w/o service?

For those of you with in-tank fuel pump/filter how many hours before they need attention?

Our X2(X1) has close to 500 hours on it and was curious if we're nearing a point where the fuel system needs service. Looked in service book but did not see any suggested hours for having things done.

I thought Andy Zarlengo on here went over 800 hours with his X5 w/o any issues a few years back. That may have been before the ethanol mix came into play though.