# How many rows?

Below is a small data set of monthly copper prices in 2006. Suppose that you wish to create a cumulative animation of these copper prices by month. How many rows are needed to create the frame for July (Jul)?

# A tibble: 12 x 4
price month   day  year
* <dbl> <ord> <int> <dbl>
1 2678. Jan       1  2006
2 2852. Jan      31  2006
3 2927. Mar       2  2006
4 3611. Apr       2  2006
5 4306  May       2  2006
6 3898. Jun       2  2006
7 4170. Jul       2  2006
8 4060. Aug       1  2006
9 4033. Sep       1  2006
10 3999. Oct       1  2006
11 3676. Nov       1  2006
12 3436. Dec       1  2006