We added them just for sake of comparison between free and premium ones as several users requested that. (colorlib.com)
For sake of a comparison, think of a child who cries at the store to get candy. (dogtrainingbasics.com)
For sake of comparison with a gasoline - powered scooter, again the Vespa S50 (which gets a bit under 90 miles per gallon and can go about 200 miles per tank of fuel, pretty darn good really...), it emits about 0.25 pounds of CO2 per mile travelled. (treehugger.com)