20 years ago.
I'd say that's about right. It was amusing until about the mid-90s for me. Then it went downhill. Its time for it to go.
However, I did watch "The Family Guy" for a few brief minutes a year ago while my two young grandsons (ages 14 and 8) were visiting for a few weeks. Happened to walk in the living room while they had that show on, and watched as "the family" was "entertaining" a hippie-looking dinner guest (obviously modeled after a "Jesus freak") whom they addressed as "Jesus Christ". The "family guy" turned to this character and asked him if he could do a miracle, and the character said "sure"--or something like that--and then grinned mischieviously while two huge boobs popped up on the front of the female character, presumably the family guy's wife.
At that moment I shouted "that's blasphemy!" and turned off the TV.
My two grandsons were more than a little startled at my outburst--and actually so was I. But--as I (as calmly as I could) explained to them--there is nothing funny about a so-called cartoon that BLATANTLY mocks or puts to scorn my Lord and Savior Jesus Christ, and a program that engages in it will NEVER again be watched in my house!