Payton collected data to show the relationship between the number of hours he practices and the number of errors he makes when playing a new piece of music. The table shows his data. A 2-row table with 9 columns. The first row is labeled number of hours with entries 1, 2, 3, 4, 5, 6, 7, 8. The second row is labeled number of errors with entries 36, 34, 30, 31, 23, 16, 11, 5.

Which is the approximate slope of the line of best fit for the data?