Careful: the link points to a chart listing Accidents, not Injuries (assuming death is a Fatal Injury). Little discrepancies like this become a big problem when complaining.
We did try with adverts on buses blaming Cars for pollution that is mainly put out by buses - and lost.
http://www.safespeed.org.uk/forum/viewtopic.php?t=3278
I live just outside South Staffs, and the trip to Leek is now a nightmare of Camera after Camera after Camera, so I have sympathy.
Assuming one fatality per accident, then the individual figures imply a raise, but you probably need to look at a rolling average to flatten out the peaks. A three year average gives 50.3, 54, 54.6, 58.3 which is a continuously rising number by anybodies standards. They might then argue that it is fatalities per X vehicle miles, in which case high numbers are acceptable if the number of vehicle miles has increased at a faster rate.
The problem is that you will be using a government funded organisation to complain about official figures from another government funded organisation, and just like Bliar and Saddams WMD it doesn't matter how obvious the truth is. If your knighthood for services to the "country" depends on not pissing of those that matter, then would you risk it?
I suggest trying (the link to the ASA web page for entering complaints is on the linked thread), but don't expect the complaint to be upheld.