First we would need to address the incorrect statistics that you provided.
You would need to compare actual missions per shuttle rather than just the number of shuttles in use. 135 Space shuttle missions vs the 5 Space Shuttles that actually flew missions.
The total number of crew members of all
135 space shuttle missions: 833.
Number of crew members that died: 14
That means that 1.680672268907563% of all Space Shuttle crewmembers died during their missions on a vehicle that traveled at speeds of 17,500 miles per hour. All things considered that's not a bad track record for what it is.
*The 2003 accident could arguably be excluded because it was the result of a completely unnecessary replacement of the standard tank foam with a harder "environmentally friendly" foam that damaged the tiles on take off and led to the eventual disaster during reentry. Apparently someone at NASA was concerned that having a relatively small piece of the safer foam fall into a swamp in the middle of nowhere was a major problem and decided to replace it with the harder Astronaut killing foam that caused the accident. A perfect example of how alarmist overreactions can cause dire unintended consequences.
The total number of passengers that flew on commercial airliners in 2017 alone was 4.1 billion. I wasn't able to find the exact statistics for the entire history of commercial aviation but based on that number it's probably safe to assume it's around 50 billion.
The number of people killed in commercial airline crashes since 1942 is approximately 75,000.
That means that 0.00015000000000000001% of all
commercial airline passengers over the past 80 years have died during their flight. We could more specific and adjust for the fact the Shuttle program only lasted 30 years but it really isn't necessary for our purposes.
In theory traveling on the Space Shuttle is 11,200x more likely to result in death than traveling on a commercial airliner.
In reality 74,986 more people have died on the statistically safer mode of transportation.