I need help to return a cross-reference:

Age/Age 20 21 22 23
20 1.25 1.26 1.27 1.28
21 1.15 1.16 1.17 1.18
22 1.05 1.06 1.07 1.08
23 0.95 0.96 0.97 0.98

Example: I need to return at horizontal age 23 and vertical age 22, the
return should be 1.08. What's the best formula to use? I've been at this
all night and I still can't get the formula correctly...please help!!!