I want to know the answer to the following question:
How long was Nanjing ranked as "severely polluted" during this wave?
All the background I'm provided with is that "The heavy smog heavily polluted central and southern Jiangsu Province, especially in and around Nanjing, with its AQI pollution Index at "severely polluted" for five straight days and "heavily polluted" for nine.". Is that enough to answer the question?