We have all wondered this, but, one thing you have to realise, is that ECN has cyclic, seasonal ebbs and flows.
When the weather starts to warm up in the US, we see less posting here from US members and more from those from the Non-US areas members.
I also think to a degree, with the number of server changes and what-not, we have lost a lot of members, due to folks not being able to log in after the server change.
I could be way wrong, but that is my thought at this point in time.
Let's face it, these days if you're not young, you're old - Red Green