How to do Math.random() in for-loop with different values?

I try to fill the array s with 9999 different sets of values m[i][random], here is the code:

let m = [[22,0],[53,0],[64,0],[45,0],[34,0]];
let l = m.length;
let s = [];
for (let j = 0; j < 9999; j++)
{
  for(let i = 0; i < m.length; i++)
  {
    let x = Math.floor(Math.random()*l);
    m[i][1] = x; 
  }
  s.push(m);
} 

But i get the same values:

console.log(s)
[ [ [ 22, 0 ], [ 53, 2 ], [ 64, 0 ], [ 45, 4 ], [ 34, 1 ] ],
  [ [ 22, 0 ], [ 53, 2 ], [ 64, 0 ], [ 45, 4 ], [ 34, 1 ] ],
  [ [ 22, 0 ], [ 53, 2 ], [ 64, 0 ], [ 45, 4 ], [ 34, 1 ] ],
  [ [ 22, 0 ], [ 53, 2 ], [ 64, 0 ], [ 45, 4 ], [ 34, 1 ] ],
  [ [ 22, 0 ], [ 53, 2 ], [ 64, 0 ], [ 45, 4 ], [ 34, 1 ] ],
  [ [ 22, 0 ], [ 53, 2 ], [ 64, 0 ], [ 45, 4 ], [ 34, 1 ] ],
  [ [ 22, 0 ], [ 53, 2 ], [ 64, 0 ], [ 45, 4 ], [ 34, 1 ] ], ...]

What am I doing wrong? How to fix it?