For some reason this file of epidemic data has become unusable on my computer. I have been compiling it weekly for nearly a year. Suddenly, a couple of weeks ago, every operation became incredibly slow. A simple attempt to copy a new week's date into 52 cells made excel unresponsive. This is not happening to me on other spreadsheets. This one is quite simple--there are no formulas in it--so I cannot understand what is happening. Thanks for any help. I attached the file.
