Spilling oil

As I wrote recently, 2013 was not a good year for moving crude oil by rail. We spilled more than 1.15 million gallons of crude oil from rail cars. This does not compare well to the previous 40 years in which 800,000 gallons of crude were spilled on the rails. Okay, we are human and accidents happen. While the total number of gallons spilled is high, it is only .01% of all crude shipped by rail. However, there have been years when no crude oil was spilled. 

Was 2013 an anomaly?