We're always looking at our rates to see if there is a better way to help our customers save. Right now there are no announcements for any rate changes but when there is a change we will have it on our blog.
With your low usage, you may be able to cut it down, even more, to keep in the small tier. We have a free eBook that has helped people cut back on data while using the phone the same way. Feel free to check it out here.