That new crimes are codified in law, such as "internet fraud", and is one of the fastest growing seems to causing more crimes, not fewer. It doesn't invalidate the comparison between years for all crimes, and unless you want to argue that newly codified crimes are less serious than old ones,There is no problem per se in including newly codified crimes in statistics. It's also perfectly fine that that this causes a rise in those statistics. It still compels caution when reading those statistics:
Let's best take a totally contrived example: Beginning with the first of December, eating Surströmming is forbidden due to new environmental protection laws. This will cause a sudden spike in the crime statistics because once acceptable behavior is now outlawed. It also causes the police to suddenly solve a higher percentage of crimes since the perpetrators are easily identifiable by their smell. Did the world get better? Worse? The statistic just tells us a naked number.
Something similar happens with fraud with help of the internet and probably more with illegal access to computer systems: People were doing it before, but it never showed up in the statistics since even though it was still as bad of a behavior as it is now, it was not illegal since there was no appropriate law.
Figures for rape and sexual molestation are rising? What does that mean? More people getting raped? Or does it mean that even though less people are raped, a higher percentage are in the position to report it? The definition of rape has - rightfully - been broadened in the last decade. In germany, rape in a marriage was only codified as "rape" in 1997 (!) (in words: nineteen nintyseven). That certainly causes a rise in the relevant statistics, but it doesn't mean that more women are raped - it just means that visibility has increased. (which, by the way, is a good thing in itself)
That's what I mean by "context matters". You can't derive any meaning from the naked numbers. In the extreme case, a rise in crime stats may "just" mean that the society decided to outlaw some specific behavior. In reality it's probably a mixed bag of a lot of reasons.
EDIT: Formatting for the quote.