Question 1051296
Go to 

http://www.graphpad.com/quickcalcs/linear1/, 

input the year values in the X column and the L values in the Y column.

View the results, and look at the "Goodness of Fit" results.  

The R square value would be 0.9538.  The square-root of this is 0.9766 to four significant places.  
This would be the correlation coefficient for the regression line.