"compressed" data format

[Gebhard Gaukler]

We frequently use the World Bank indicators and so we have cached most
of the indicators in our local database.
The problem is, that I have to refresh the data two or three times a
year to get all the changes in the history. The API returns value by
value with all the metadata for every observation and that means a lot
of network traffic. I am missing a parameter to get complete time
series in a more condensed form.

Proposal:
A great feature would be to generate a difference file: Often there
are no changes at all and it would be nice to get only the changes
since a given timestamp.

Regards
Gebhard