Cotulla hired a gardener for one year to tend her flowers. She wants to know if the gardener actually helped increase the number of flowers in the garden. Her friend Kathleen did not hire a gardener. They compared the number of flowers among the 12 varieties of flowers in their garden by type of flower and recorded them. The data is below.

Cotulla's flowers: 14,12,20,22,24,20,28,27,25,14,25,23

Kathleen's flowers:14,18,19,8,10,21,17,18,22,15,20,13

They concluded that the gardener actually helped increase the number of flowers in Cotulla's garden. What is the difference in the mean number of flowers in the two gardens? (Answers are rounded to whole numbers.)