Notes:
"Incidents" includes spills.
Data for 1993 through 12/31/2006.
Number of investigated incidents per year ranged from lows of 4 in 1993 & 2005 to a high of 40 in 1996.
Year reflects when the investigation was completed.
 "Primary Cause" is the over-arching or summary factor that was seen as most contributory by the investigator, not the ‘immediate cause.’