Using pandas to download IBM stock data for year 2020 into a DataFrame, calculate and print the variance of close values using Variance formula:

xi is the stock close value on day i, x is the mean (average) of all stock close values in 2020 and n is the number of rows in the DataFrame (equal to number of days the stock exchange was open in 2020). Print rounded to two decimal places.

Please do not use any built in pandas, NumPy or math functions that calculate average, variance or standard deviation.