There are (at least) three things you need to keep in mind when you read stuff like this:
1. What is the denominator? How many cyclists were riding their bikes or how many miles were ridden, or even how many hours were spent riding between the 2 time periods? Without such data, it’s impossible to make meaningful comparisons.
2. What were the causes of death, trauma or illness, were motor vehicles involved?
3. KSI (killed or seriously injured) is a misleading term. ‘Seriously injured’ in this context means anyone taken to hospital after a crash, no matter how trivial the injury, even if they were discharged with no treatment required.
Statistics are like a bathing suit, what they reveal is suggestive, what they hide is vital.