D1 = 1st quarter of the year 1958
F4 = 4th quarter of the year 1960
G2 = 2nd quarter of the year 1961
H4 = 4th quarter of the year 1962
L1 = 1st quarter of the year 1966
Y2 = 2nd quarter of the year 1953
R3 = 3rd quarter of the year 1972
awesome! thanks. I was hoping some were older but at least I understand how to read that chart better now!