sieve percentage not working

{
  "recipes": [
    {
      "id": "minecraft:gravel",
      "meta": 0,
      "behavior": "meta_ignored",
      "rewards": [
        {
          "id": "minecraft:flint",
          "meta": 0,
          "amount": 1,
          "baseChance": 90
        }
      ]
    },
	{
      "id": "minecraft:gravel",
      "meta": 0,
      "behavior": "meta_ignored",
      "rewards": [
        {
          "id": "minecraft:glowstone_dust",
          "meta": 0,
          "amount": 4,
          "baseChance": 45
        }
      ]
    },
	{
      "id": "minecraft:gravel",
      "meta": 0,
      "behavior": "meta_ignored",
      "rewards": [
        {
          "id": "minecraft:redstone",
          "meta": 0,
          "amount": 1,
          "baseChance": 40
        }
      ]
    },
    {
      "id": "minecraft:leaves",
      "meta": 0,
      "behavior": "meta_specific",
      "rewards": [
        {
          "id": "minecraft:sapling",
          "meta": 0,
          "amount": 1,
          "baseChance": 50
        }
      ]
    }
  ]
}