His final one was 2017, according to IMDb. He died at the age of 93. So, his acting career covered 91 years in which he racked up 344 acting credits.
A bit of a caveat, his final credit was a Jekell and Hyde remake that was filmed in 2014 but not released until 2017. He filmed his last line a week before his death.
He pretty much had a credit everyone of those active years. The only years, up till his death, I didn't find a credit was 2003 and 2013.
I'm sure I had heard of him but never really gave him much thought till I saw him in Night at the Museum, which is insane given his body of work. But the past few years I've kind of become obsessed with watching older movies and TCM and it's unbelievable how popular he was back in the 30's and 40's.
How nice to be able to do something you love for that long. However, I have heard he was a pretty big jerk.