I was looking back over some of your earlier under-sea stuff, to reference it for an IGMS column, and wondering why that stopped. Did that well run dry (to mix a metaphor) or were you just making more $ off other topics?

I'm trying to figure out a way of estimating the proportion of SF that is set in space vs the sea. Lots of people have complained about funding for NASA vs NOAA, but I haven't found any statistics for story themes, and my searches of Google's Ngram viewer have been less than satisfactory. Any thoughts?