Since 1995, there have been more than 2,000 significant accidents involving pipelines carrying crude oil and refined petroleum products that have caused about $3 billion in property damage, according to data from the federal office that oversees pipeline safety, the Pipeline and Hazardous Materials Safety Administration. That's an average of a little over 100 per year. But after dipping to 77 in 2009, that figure has spiked to at least 121 in each of the past two years.