Country Walking magazine travels through space: 1000 miles in 2018

On the Country Walking magazine "Walk 1000 Miles in 2018" chart, it claims that we move 137 miles through space every second. The Earth is 93 million miles from the Sun. Assuming a circular orbit, the distance is 2 x pi x radius = 584 million miles a year. In a year there are 365.25 days x 24 hours x 60 minutes x 60 seconds = 31.6 million seconds. 584/31.6 = 18.5 miles in one second. The distance due to the rotation of the earth about its axis is much smaller. The earth also rotates around the Milky Way https://starchild.gsfc.nasa.gov/docs/StarChild/questions/question18.html gives the speed as 828000 km/hr so that means 230 km per second. That's 144 miles in one second. This is probably the source of their statistic but http://www.physlink.com/education/askexperts/ae548.cfm gives a different figure for movement relative to the microwave background radiation. I do love a good statistic!