If I may, I'll address first the question of net worth.
As you might imagine, net worth is a bit of a moving target. It fluctuates day to day with market rates, interest rates, and circumstances on the ground. We do have, however, in the public accounts an indication of the book value of those 46,000 to 47,000 properties, and that number comes to $26 billion. I stress that this is a number that fluctuates with circumstances and over time.
As for the age of those properties, you're right, many are quite old. While I don't have a number for you on the average age of all 46,000 or 47,000, I can tell you that of the approximately 7,000 properties held in the Public Works portfolio--granted, a very small slice of 47,000--the average age is in the order of 40 years.