Camera movement help

Im trying to make my camera speed up gradually till a maximum speed of 2.5f from 0.1f. How would I go round doing this?
thanks in advance/

using UnityEngine;
using System.Collections;

public class CameraMovement : MonoBehaviour {

	// Use this for initialization
	void Start () {
	
	}
	
	// Update is called once per frame
	void Update () {

        transform.Translate(Vector2.down * 0.16f);
        if (transform.position.y == 4)
        {
            transform.Translate(-Vector2.down * 0.16f);
        }
        if (transform.position.y == -4)

        {
            transform.Translate(Vector2.down * 0.16f);

        }
    }
}

That’s a strange script. So if you start from higher than 4, it will go down to 4 and get stuck there, but if you start from lower than 4, it will keep going down, moving twice as fast for 1 frame when at -4? Unless the camera is upside-down or something. I’m not going to touch that part since I am not really sure what you’re trying to do with it. Also, since you’re using Update, is there a reason you’re not using Time.deltaTime to move the camera?

Either way, to answer your question, you could do something like this to speed the camera up:

 public class CameraMovement : MonoBehaviour {

      float speed = 0.1f;
      float speedIncrement = 1.1f; //how fast it increments. tweak this number around to make it slower or faster
         
      void Update () {
           if (speed<2.5f) speed*=speedIncrement;
           if (speed>2.5f) speed = 2.5f;
           transform.Translate(Vector2.down * speed);
      }
 }