I FOUND YOUR COMPLETE QUESTION IN OTHER SOURCES.
PLEASE SEE ATTACHED IMAGE.
First, we define the variables:
x: number of years after 1950
f (x): amount of vinyl sold.
Then, with the variables defined, we have:
68594 vinyl records were sold in 1958 ---------> f (8) = 68594
91299 vinyl records were sold in 1961 ---------> f (11) = 91299
38720 vinyl records were sold in 1952 ---------> f (2) = 38720
161743 vinyl records were sold in 1967 ---------> f (17) = 161743
