i would graph with a date Histogram the evolution of unique count of a term (lets call the value "projects"). It should be a cumulative value.
if you can help to do that it will be great.
The next step will be to start to the real value that's mean not 0.
For example, i want to see the evolution of number of projects for the last 3 months, i want to calculate all the number of projects created befaore the 3 month and start the graph with this value.
Does it possible ?