The replacement interval is 105 months or kMiles but the inspection is 30,60,90 months/kMiles. Sounds like it was good you had the 90K "inspection".
Many people forget the Months bit which can catch you if you don't drive many miles every year. Those numbers mean if you have a 2002 or older it is probably time to do it. Rubber parts and petroleum based products fail over time regardless of use/wear. I almost wrote that as "rubbers and lubricants".
