My general understanding is that an outstanding amount of tax debt in that range is not unusual for types of businesses. What makes us unusual is the sheer volume--$18 billion is $18 billion. It's a difficult number to ignore, even if it is only 5% or 6% of the total amount that we collect every year.
The main difference between us and the private sector, as you pointed out, is that we don't choose our clients. They enter the system without our permission and we have a duty to collect. On the one hand, we probably have the toughest measures available to collect tax debt in the country. On the other hand, we're held to a standard by parliamentarians and the public in the manner in which we collect debt, so we want to ensure our approaches are fair and reasonable.
We have measures available for individuals who cannot pay to stage their payments. In an exceptional circumstance, where we think there are factors beyond the control of the individual, we can relieve interest on penalties. We have tools to make it more palatable to pay, but at the end of the day, we will always have a certain number of people who get in over their heads, and in spite of our best available tools, we will not be able to collect.