Can't say that's a good indicator at all. The percentage has been near the same forever. It's actually on a decline now, as you mention. Could be any number of reasons as to why.
Like I said, there is no way to prove it, but ARRL membership is probably the only “number” you can point to that might even remotely suggest relative ham activity. Very, very, few of the inactive hams I know are members, and a fair percentage of the active ones, although by no means most of them, are.
That decline in percentage of hams (who are ARRL members) has been going on a long time, I would say well over 20 years. But it is very slow decline, and has been on about the same curve a long time. However, like I said before, although the percentage of licensees who are ARRL members is indeed slightly down, the raw number of hams who are ARRL members is up. If the number of ARRL members is in any way linked to the number of active hams that would indicate an upwards trend in active hams.
But again I will ask, what would be considered “active”?
Although it has been a while, I don't remember the last solar cycle being like this at all. 20m is really unaffected, and 40/80 actually improve generally during the low cycle. Those seem dead too, at least compared to what they used to be.
This is, without a doubt, the worst solar cycle I have experienced in my 50+ years as a ham or listener. 20 meters is a shadow of its possible conditions, even for a cycle null. 40, 60, 80, and 160 meter conditions have actually improved, however I find more and more that people are not as interested in those bands. They want long DX, and even when very good 40 and 80 can’t hold a candle to 20. So I think this is driving down general casual HF operations, even when the band is indeed good. This same thing happened in the last couple of solar cycles, but this does seem to be more pronounced. I hear otherwise active new hams say things like “I am going to wait until the cycle improves to get on HF” or some similar nonsense.
With that said, 40, 80, and 160 still seem to be getting good use, and 60 meter activity is possibly higher than I have ever seen it.
Tuned across the 20 meter and 40 meter bands yesterday evening. Dead, dead, dead.
One CW CQ (some guy in 7 land) and that was it.
Odd, I was on 40 last night, and there was quite a bit of traffic. I would not say the band was packed, but spinning the dial tuned across many conversations, not bad for a Tuesday night. I did not check 20, but it would not surprise me if it was dead, the 3000 km MUF was well below 8 MHz last night.
Right now, before sunrise local time, I am looking at 40 and 80 meters on a waterfall, using a suboptimal antenna (antenna is actually a VHF-Lo ground plane on the roof of the building).
On 40 meters there is a lot of CW activity in that band, a couple dozen QSOs at least, FT8 looks very active, there is some JT65 (although less than the FT8), and there are a good dozen plus voice conversations going on between 7125 and about 7210 kHz, above 7210 kHz I see no SSB, but that might be because of the BC stations hammering that freq range.
On 80 meters I see a couple dozen SSB signals from 3600 to 4000 kHz, mostly 3800 and up. CW activity on the band looks good below 3600 kHz, but not as active as 40 is. For some reason I do not see the FT8 or JT65 activity as high on 80 as it is on 40, there is some present, but not as much as on 40.
160 an 20 meters also show some activity right now, 160 will die after sunup but 20 will pick up.
T!