While waiting 'patiently' for Prince of Fools to click over 20,000 Goodreads ratings I took the time to chart where all of my books stand in terms of Goodreads ratings. Red Sister is punching above its weight and looks to be ready to overtake Prince of Fools despite being three years younger!
I also made a very rare dip into the PenguinRandomHouse author portal for some actual sales figures. This is how many books I sold in America over the last 7 days.
But take the 106,000 US sales (including Canada) add another 106,000 for my near identical UK sales (including Australia and New Zealand), and that 212,000 a year is a decent ballpark figure for my annual sales in English. If you took that over the 7 years since Prince of Thorns was published you would get ~1.5 million sales, which again is a decent ballpark figure for my total sales in English.
...and after all that, Prince of Fools is still stubbornly clinging to 19,986 ratings...