As you have alluded to, it's a bit of a challenge in terms of definition, but we use the figure generally of about 750 lighthouse-like structures, and within that there are about 250--give or take--that are what we would call major lights, and then another 500 or so smaller structures, which many in the public lexicon, for example, would refer to as lighthouses. That's where we get the number.
As you saw in one of our scenarios, we talked about using the same approach that the Heritage Railway Stations Protection Act uses, under which about 60% of the available railways are actually designated. That is not to say the same process would be followed here, but if it were, 60% of our 750 would be roughly 450, and that was the premise that allowed us to come up with a higher estimate. Our figure for DFO is roughly 750, and then there is another discussion around what is actually going to be included as a lighthouse in the context of this bill. My colleague from Parks spoke to the additional equipment or buildings that--depending upon how the bill is interpreted--could be included as light stations or lighthouses.