Deaths per mile travelled for planes and cars designed and built before 1930, for a fair comparison. The Graf Zeppelin launched in 1928 did 1,000,000 miles with

Deaths per mile travelled for planes and cars designed and built before 1930, for a fair comparison. The Graf Zeppelin launched in 1928 did 1,000,000 miles with no crashes, deaths or injuries. How many other vehicles from the 1920s were that capable and safe?