Refactor code structure for improved readability and maintainability

data/years.json

@@ -1816,8 +1816,8 @@
       "mbid": "e9eb684a-5c5a-485e-ac76-ce799aeba7a0"
     },
     "The Beach Boys - Surfin' U.S.A. (Mono).mp3": {
-      "year": 2008,
-      "date": "2008-06-10",
+      "year": 1963,
+      "date": "1963",
       "title": "Surfin' U.S.A. (Mono)",
       "artist": "The Beach Boys",
       "mbid": "fa52f01e-6c8c-46ff-860d-daa4930f93a4"
@@ -5176,8 +5176,8 @@
       "title": "Under Pressure",
       "artist": "Queen, David Bowie",
       "mbid": null,
-      "earliestDate": null,
-      "year": null,
+      "earliestDate": "1981",
+      "year": 1981,
       "error": "No recordings found"
     },
     {
@@ -6151,8 +6151,8 @@
       "title": "China In Your Hand (Single Version)",
       "artist": "T'pau",
       "mbid": "56a5d0fc-a0c3-4e07-91b5-0c8c77b43ab2",
-      "earliestDate": "2009-06-08",
-      "year": 2009,
+      "earliestDate": "1987",
+      "year": 1987,
       "confidence": {
         "mbScore": 100,
         "titleSim": 1,