CREATE TABLE table_2950 ("Condition" TEXT, "Prothrombin time" TEXT, "Partial thromboplastin time" TEXT, "Bleeding time" TEXT, "Platelet count" TEXT)

What is the prothrombin time of von willebrand disease?
SELECT COUNT("Prothrombin time") FROM table_2950 WHERE "Condition" = 'Von Willebrand disease'
SELECT COUNT("Prothrombin time") FROM "table_2950" WHERE "Condition" = 'Von Willebrand disease'