Invoke after every loop of "if" statement?

So I have a very basic script to test the increment of an integer called "wood". I have a method that contains an if loop that increments wood by 1 if it's less than 10. I want wood to increment every 2 seconds so I set an invoke in the Update method. The problem is, after the first two seconds, the wood is fully incremented instantly instead of over time. My script is this:

 using UnityEngine;
 using System.Collections;
 
 public class AddWood : MonoBehaviour {
     public int wood = 1;
     void IncreaseWood() {
         if (wood < 10) {
             wood++;
             print (wood);
 
         }
 
 
     }
     void Update() {
 
             Invoke ("IncreaseWood", 2);
 
     }
 }