Hi I have a question regarding correlation calculation in Excell:

What does this question mean:

a. Calculate the correlation between Altalnta and Denver for the 1990:1-2016:1 time period ( I don't understand the 1990":1" part ) On the excel page it shows like this: ( but it goes all the way to year 2016, I only included 1990 and 1991 ) How do I calculate this? Does the ":1" mean I only have to consider that period?

Year Q Quartely return - CRE_Atlanta_GA Quarterly return - CRE_Denver_CO

1990 1 1.90% 0.34%

2 0.25% 1.28%

3 -2.18% -0.10%

4 -1.87% -3.34%

1991 1 -2.23% -2.10%

2 0.70% -0.51%

3 -1.05% -0.31%

4 -6.05% -4.34%