I have two arrays, each containing a years object with year key-value pairs and a value. I want to create an updated version of array1 with the values for the years in each row reduced by the values of the corresponding values in array2

i.e. A/Fred/2013 should be reduced from 16 times 3 to 13 and so on.

So far I have done it, but I can't update the array correctly.

 array1.forEach(r1 => {
 // Get the corresponding row from array2
 let array2Record = array2.find(r2 => r2.key1 === r1.key1 && r2.key2 === r1.key2);
 // Go through each of the years for this row in array1
 Object.entries(r1.years).forEach(keyValuePair => {
 // And reduce it by the value in array2
 keyValuePair.value = keyValuePair.value - array2Record.years[keyValuePair.key].value;
 })
})

This is the simplified version of the data.

 let array1 = [
 {
 "key1": "A",
 "key2": "Fred",
 "years": {
 "2013": 16,
 "2014": 11,
 "2015": 17
 }
 },
 {
 "key1": "A",
 "key2": "Jim",
 "years": {
 "2013": 1,
 "2014": 4,
 "2015": 3
 }
 },
 {
 "key1": "B",
 "key2": "Mary",
 "years": {
 "2013": 1,
 "2014": 4,
 "2015": 3
 }
 }
]

let array2 = [
 {
 "key1": "A",
 "key2": "Fred",
 "years": {
 "2013": 3,
 "2014": 2,
 "2015": 7
 }
 },
 {
 "key1": "A",
 "key2": "Jim",
 "years": {
 "2013": 9,
 "2014": 3,
 "2015": 1
 }
 },
 {
 "key1": "B",
 "key2": "Mary",
 "years": {
 "2013": 8,
 "2014": 3,
 "2015": 6
 }
 }
]