Generating statistics on the internet of various modes of ham radio seems to be a trend, although I am not sure why.
At the top level, keeping statistics on amateur radio licensing trends has been something I've noticed for the last 10 or so years. A few times a year there seems to be a post on QRZ.com on this.
While somewhat interesting, I really don't think it is an accurate gauge of anything. There are thousands of amateurs holding licensees, but are not active on the radio or in research and development endeavors.
There is a list of live Winlink packet stations. As well as the live statistics of D-Star repeaters and active users.
I never understood why one must register to use their D-Star radio over the gateway network. If remote people on D-Star can't hear you it's because you aren't registered. Now I understand why this inconvenience exists. For the sake of being able to generate and advertise the total number of people using this mode.
There are also statics for IRLP, as well as hams experimenting with APCO-25.
Like I said, I'm not sure what all this statistical data goes to prove. Is it supposed to impress you that there are 900 active IRLP connections and 17 billion registered D-Star users?
And what about some of the modes that don't have anyone taking statistics? How many people are really active with ATV (amateur television)? Or, hellschreiber?
Are these numbers meant to try and sway you into trying a new mode? Or make you feel like you missing something?
Once upon a time, years ago... hams used to experiment and try new modes and things because they were interested in that sort of thing. Now apparently hams need to be peer pressured? And what about those that are content on whatever mode most interests them?
If you are interested in electronics and radio theory, I encourage you to get into the hobby regardless of the statistics. This isn't a high school polarity contest folks. Please don't consider exploring a new facet of the hobby only because that is what is advertised as popular, and not because you have a bonafide technological interest.
Developing a deep technological interest based on a curiosity of "how it works" helps the hobby. Anything else only helps inflate numbers for a fad.