Statistics are abused all the time aren't they ?
You cannot compare these figures, unless they are subdivided by journey charecteristics. For eg:
Gather all these measures for say journeys made by each mode for all UK domestic air routes. Ie, deaths per passenger journey, Edinburgh-London by Air, Coach, Rail, Car, Van, etc.
The inapproriate use of the broad brush figures is best highlighted by the Bus figure. This is skewed immensely by the very high volume of short, urban, low speed journeys, where most accidents are minor bumps and scrapes, but the incidence of them is quite high (ie there are lots of accidents, but not many deaths). However, most passenger deaths by road public transport will be on long distance higher speed services. You will struggle to find data on Inter-city bus and coach deaths, but I would suggest that a trawl of the BBC news website for the past 5 years will show up many more UK deaths than equivalent domestic air transport.