I've started to check up on plots. Went through 180 of them (Lavender Beds, Ward 1, 8, 3 [1-30], 6 [31-60]) and found 22 more likely to be inactive or 39 less likely to be inactive. If you only take the more likely inactive plots you have about 12%, let's say 10% are inactive - that would make about 144 from the total of 1440 plots. However my sample is somewhat small (12.5%) and there might be a few people who don't play but still pay a subscription.