Gyrineum bituberculare Info?

[sakura-of-the-sea]

I was just wanting to know if anyone knew the recent occurrence of Gyrineum bituberculare (e.g. Abundant, Common, Rare & all in-between)? I catalog my species with index cards & like to include the abundance of my shells as part of my data. I am including the year of known occurrence, in case it fluctuates. Any help would be great! <img src="images/smiley/smile.gif" alt="" border="0" />