/*
     element . textContent //> "0000 - 1000<br>1001 - 2000";
*/

 var result = element . textContent
 . split ('<br>')
 . reduce ( ( a , b , c )=>{
     let i = b . split ('-');
     let s = + i [ 1 ]; i = + i [ 0 ];
     while ( i < s ){
         a [ i ] = b ;
         i ++
     }
     return a ;
 },[ ]);

 console . log ( result [ 1252 ]);
 console . log ( result [ 53 ]);