Let's say 1000 dollars was spent on all of these. That would mean 170 dollars and 240 were spent on food and entertainment respectivly. If we want to see how much of the total cost was spent on these things, we would have to add them and divide them by 1000, so:

Answer: 3.6 feet per year
Pick any column and divide the feet over the years
eg: 7.2/2 = 3.6 (column 1)
You can think of it as the ratio
7.2 feet: 2 years
and then divide both sides by 2 to get "1 year" on the right side
7.2 feet: 2 years
7.2/2 feet: 2/2 years
3.6 feet: 1 year
The answer is "while".
"While foot binding was promoted as a way to achieve ideal beauty, in reality, it horribly disfigured a woman's feet."