A lawn care company keeps records of the temperatures for each day of the summer as well as the number of clients that request mowing services. The company believes that the number of clients depends on the heatsome people don't want to mow when it's very hot. The following are the data for each of six weeks from this past summer--both the number of 90+ degree days in that week and the number of clients requesting mowing services. (This chart extends to the right...you may need to scroll to see the entire dataset.)

# of 90+ degree days376275# of clients141715142118

What is the standard deviation of the number of clients?