[Developers] Generalizing 'Dated Integer' type

[Jeff Thompson]

The type 'Dated Integer' is now used in a few places, such as the population of a City/Town.
The population also allows multiple values for the purpose of showing the population change over time.
For example, see the population of San Francisco:
http://www.freebase.com/view/%239202a8c04000641f8000000000061a55

It had a value for 2006, but I added a historical one for 2000 from the US Census.

1.  Since 'Dated Integer' is a compound type, you can add more info to it.  I made a co-type
called 'Cited Value' which has a property 'Citation'.  Now I can cite the 2000 Census for the population value:
http://www.freebase.com/view/%239202a8c04000641f8000000005b9bc07
Is this a good way to do citations?

2.  How does MQL handle a query for "cities with population over 100,000" since a City/Town population
is not a simple unique-value integer?  What happens when you just want a table of cities and their populations?
Is there generalized support for looking through the list of 'Date Integer' values and finding the latest one?
Which brings me to...

3.  The only other "Dated" type I see is 'Dated Money Value' used, for example, to track the 'Street Price' of
a 'Digital Camera'.  The same problem applies for a query to find a camera under a certain price (the latest price).
I would expect wanting many more "Dated" types, for example a 'Dated Float' for the weight in the Person type
so that I can track my weight.  This is a general need.  The date field is a different property
in 'Dated Integer', 'Dated Money Value' and any future 'Dated Float', etc. so that there has to be a different
query for all of them.  Furthermore, without a standardized date field it is difficult to query across them,
for example to display them together on a timeline.  Have you thought about generalizing so that a property
of any type to become a "Dated" type in a standard way?

- Jeff (user jefft0)