I want to know the answer to the following question:
How many years did Ali Qushji spend in Istanbul?
All the background I'm provided with is that "Another example is Ali Qushji -an astronomer, mathematician and physicist originally from Samarkand- who became a professor in two madrasas, and influenced Ottoman circles as a result of his writings and the activities of his students, even though he only spent two or three years before his death in Istanbul.". Is that enough to answer the question?