How has the Price per earning (P/E) ratio for walmart and Tiffany's changed ( up and down) and why? what is driving the trend in movement of the P/E ratio . How is the P/ E of these companies compared to other companies in the same industry?

How has the P/E ratio for Wal-Mart and Tiffany's changed over the last few years? what is driving this movement of the P/E ratio and how is the P/E ratio of Walmart and Tiffany compared to companies in the same industry.