I have a data set containing information about buildings, such as the area code, the neighborhood code, the number of floors, the year in which the house was built and the year in which restorations were made. All of them are integers.
I want to see if any of these variables are strongly correlated to the number of incidents reported in the house (such as problems with the heating, fire alarms etc.). I looked at the correlation matrix and there seems to be almost no correlation between the number of incidents reported and the data.
I'm wondering whether I'm applying the wrong method and whether there is another way of finding a correlation between the two. How do I make a distinction between, say, a 4-digit number that represents the ZIP code and the year in which the house was built?