How do I change only one person's stats on leaderboard?

I just started Lua five days ago and I did a little bit of research and I am making a difficulty chart obby. I am making my leaderboard for the obby which tells you which stage you are on and which difficulty you are on. When I tested my leaderboard out in the studio with two players, when one player stepped on the first checkpoint, the leaderboard updated for all players. Is there any way I can fix this? I will show my code down below. Help is very appreciated and thank you in advanced. :)

local players = game:GetService("Players")

players.PlayerAdded:Connect(function(player)
	if player then
		local folder = Instance.new("Folder")
		folder.Name = "leaderstats"
		folder.Parent = player
		local stage = Instance.new("IntValue")
		stage.Name = "Stage"
		stage.Parent = folder
		stage.Value = 0
		local DifficultyChart = Instance.new("StringValue")
		DifficultyChart.Name = "Level"
		DifficultyChart.Parent = folder
		DifficultyChart.Value = "None"
		local checkpoint1 = game.Workspace.Checkpoint1
		checkpoint1.Touched:Connect(function(hit)
			local humanoid = hit.Parent:FindFirstChild("Humanoid")
			if humanoid then
				stage.Value = 1
				DifficultyChart.Value = "Too EZ"

				local checkpoint2 = game.Workspace.Checkpoint2
				checkpoint2.Touched:Connect(function(hit)
					local humanoid = hit.Parent:FindFirstChild("Humanoid")
					if humanoid then
						stage.Value = 2
					end
				end)
			end
		end)
	end
end)