Back in 2013, I used data from BellBoard to estimate the number of handbell ringers - or at least, the number of people who had rung a published handbell peal or quarter during a certain period of time. I found 1059 people during the 5-year period up to the end of June 2013, and 1306 people during the 10-year period with the same end date. There are some inaccuracies due to inconsistent reporting of names, which I wasn't able to completely compensate for, but I concluded that 1300 was a reasonable estimate of the number of handbell ringers at quarter peal standard or above.
I'm shocked to see that it's more than 5 years since I did that analysis (time seems to pass more and more quickly), as I have a clear memory of sitting at Tina's parents' dining table and writing the little program that extracted the data from BellBoard and analysed it. But on the positive side, 5 years later seems like a good time to repeat the analysis and see whether anything has changed.
For the 5-year period up to the end of December 2018 (yes, I should wait until next Tuesday, but I don't have a lot to do today), there are 1117 people, which is slightly more than for the 5 years up to June 2013. For the 10-year period up to the end of December 2018, there are 1573 people. And if I go all the way back to January 2004 to look at a 15-year period, there are 1903 people.
My conclusion is that the statistic consisting of the number of published handbell ringers during the previous 10 years, has increased from 1306 in June 2013 to 1573 in December 2018. And there are another 300 or so people who rang a peal or quarter more than 10 years ago.