Muslims who came from central asia did not come in millions, 25% is a very large number and is an incorrect index.
Kashmir valley is a typical example…kashmir was ruled by foreign muslims and many muslims from central asia visited valley and stayed over there.
Foreign muslims who continued to stay in Kashmir is very less. Its absolutely not in double digits, just becoz you have converted to islam and adopted “Khan” or "durrani"as surname does not mean you are a muslim from central asia