While research shows that avocados contain the sugar molecule D-mannoheptulose, we do not have any source of how much is in a serving of avocado.
Based on the USDA nutrient database, we do know that a 1-oz serving of an avocado contains 2.6 grams of carbohydrate. The current analyses that have been completed on the California fruit do not get into the specific types of sugars in the fruit.
For a complete analysis, you can visit the USDA Web site at
http://www.nal.usda.gov/fnic/foodcomp/search