Alternative to look up in excel in Javascript

JavaScript
#1

Respected sirs,
I have a 2 column table with more than 40 rows. data is arranged as under.

column 1            column2
head-AGE          Pension value
40                        15
41                       14.90
42                        14.45
43                         14.10

and so up to 80
Being new to JS , I could find the way as given in look up
object for finding a value in reverse alphabet .
However for that I have to type all the 80 rows data as an object.
for example.

function pensionLookup(val) {
var result ;

// Only change code below this line
var lookups ={ 
   40:
     15,
  
 50:
 14,
    
 60:
 13,
    
 70 :
 12,

 80:
 10
}
result = lookups[val]
// Only change code above this line
return result;
}
console.log(pensionLookup(70)); //12

for that I have to type manually all the rows data from excel table as given above.
I shall be highly thankful if I am advised:

  1. Whether my approach is correct or not if I don’t want to use XL. lookup; I have to use ‘result’ further to calculate the commuted value of Pension.
  2. what are other ways to tackle this.
  3. any other advice welcome.
    regard
#2