I've known of property and other crimes that did not show up in the statistics/annual reports of a particular city. The city in question was/is known for low crime and used that as a selling up point to attract businesses and home buyers. I'd be surprised if this was the only municipality that "fudged" their numbers.
This could not be more true where I live, and with police departments shrinking nationwide, I would guess that it's true in other places as well.
Plenty of people are still getting their back doors kicked down while at work, and come home to find their laptops and consoles, and television missing.
You call the police, and they'll show up 4 hours later, and all they really do is put your name on a list. It's basically up to you to go around and search pawn shops and craigslist to find your stuff.
Most people don't even bother to call the cops, and don't bother filing an insurance claim since an LCD TV is $450 and the insurance deductible is $1500, not to mention the rise in rates or risk of getting your coverage dropped.
Reported crime is down. That's about it.
2) For simple thefts, of course, a large portion is not reported because people don't bother - but are you really arguing that in suddenly all the (very different) countries people started reporting crimes much less than 20 years ago; or that municipalities in 2000'ies are fudging numbers much more massively than they could in 1980's?
(not that numbers can't be fudged, just that if you were fudging numbers you wouldn't fudge them that much)