I'm not an expert on this subject, but those numbers don't look that high to me. It's my understanding that a log takes about a year per inch of thickness to dry. On a 1" thick board, that ends up being about 6 months (since it's drying from both sides). Depending on the average relative humidity where you live, 7% to 11.5% moisture content in 6 months seems pretty reasonable. When I'm drying something like a turned bowl or other piece made from fresh wood, I primarily watch to see when the numbers stop dropping. Once the moisture content stops changing, then I know that piece of wood is as dry as it's going to get.