Did all 27 of these drives fail on your personally, or at an organization you work for? What period of time did they fail? And out of how many TOTAL drives that were available over the ENTIRE time period?

In other words, was it 27 drives that failed out of 27 (NOT!) or 27 out of a total population, or the entire period of time you collected them, of 27,000? It makes a difference.