Newer model crash test vs older model crash test: which is safest?

[femmefatales]

My 2002 Jetta VK was just totalled in a head-on. Thankfully, no major injuries. I am shopping to replace the car, and as one can imagine, safety is my top priority. I am looking at VW Jetta (2010) and Passat (2009). It's difficult for me to compare one model year to another - where both cars recieve top picks - one may have a four star on one test and five star on another; and the other model vice versa.

My main question is this: I noticed that the car I was driving, a 2002 Jetta, had a HIC (Head Injury Criterion) of 373 for years - until the new model year 2005-2011 where it was redesigned. It now gets a HIC in the 540s, which from my understanding, the newer model has a higher risk of injury than the 2002 model. All hte VWs now het scores for HIC in the 500s, and no longer in the 373 range. Is it possible they changed the testing criteria and all cars are graded differently after 2005- or, does this mean that the newer models are not as safe as the 2002 models? Am I comparing apples to oranges, or getting too obsessed with crash test ratings? Does anyone have any insight as to do these scores really translate into a less safe vehilce? One would think a newer model year would have improved safety features. They may all still get 4-stars, but a higher score- does that mean less safe? Many thanks!