numbers increasing after specific time duration

I want to create a increasing numbers. for example 1-100. so i tried to invoke my number method in void Update (), it changes numbers very quickly. what i want is changing numbers every few seconds for ex after every 5 second it should increase number and show in GUItext. i also tried with thread sleep but still could not get exact result. please help me, thanks in advance.

Define a float number:

float myNumber;

Then in Update do this:

myNumber += Time.deltaTime * (1.0f / 5.0f);

There are a bunch of ways you could do this. You could try InvokeRepeat.

private var number : int = 0;
private var maxNumber : int = 100;

function Start(){
	InvokeRepeating("CountNumber", 0, 5);	//Repeat the CountNumber function, start after 0 seconds, repeat every 5 seconds.
}

function OnGUI(){
	GUI.Label(Rect(900,20,300,300),String.Format("Number: "+ number));	//GUI display
}

function CountNumber(){	
	if(number >= maxNumber) {
		number = maxNumber;				//Making sure the number doesn't get larger than it is allowed to
		CancelInvoke("CountNumber");	//This stops the method from repeating, It has already reached the max.
	} else 
		number++;						//Increase the number count by 1	
}