Problem whit score system?

Hi, im making a Train of though clone (a luminosity.apk game from the playstore). In my score system, the player gain a point everytime a train collide with a house of the same color. I made every train and house an independnt GameObject, and I atached this piece of code to every house.

 public int puntos;


 // Use this for initialization
 void Start () 
 {
     puntos = 0;    
 }

 void Update () 
 {
 }

 
 void OnTriggerEnter (Collider other)
 {
     if (other.gameObject.name == "TrenRojo" && this.gameObject.name == "CasaRoja")
     {
         other.gameObject.SetActive (false);
         IncrementarPuntos ();
     }
     else
     {
         other.gameObject.SetActive (false);
     }

     if (other.gameObject.name == "TrenRojoO" && this.gameObject.name == "CasaRojaO")
     {
         other.gameObject.SetActive (false);
         IncrementarPuntos ();
     }
     else
     {
         other.gameObject.SetActive (false);
     }
 
     if (other.gameObject.name == "TrenAzul" && this.gameObject.name == "CasaAzul")
     {
         other.gameObject.SetActive (false);
         IncrementarPuntos ();
     }
     else
     {
         other.gameObject.SetActive (false);
     }

     if (other.gameObject.name == "TrenVerde" && this.gameObject.name == "CasaVerde")
     {
         other.gameObject.SetActive (false);
         IncrementarPuntos ();
     }
     else
     {
         other.gameObject.SetActive (false);
     }

     if (other.gameObject.name == "TrenVerdeO" && this.gameObject.name == "CasaVerdeO")
     {
         other.gameObject.SetActive (false);
         IncrementarPuntos ();
     }
     else
     {
         other.gameObject.SetActive (false);
     }

     if (other.gameObject.name == "TrenNaranja" && this.gameObject.name == "CasaNaranja")
     {
         other.gameObject.SetActive (false);
         IncrementarPuntos ();
     }
     else
     {
         other.gameObject.SetActive (false);
     }

     if (other.gameObject.name == "TrenMorado" && this.gameObject.name == "CasaMorada")
     {
         other.gameObject.SetActive (false);
         IncrementarPuntos ();
     }
     else
     {
         other.gameObject.SetActive (false);
     }
 }

 void IncrementarPuntos ()
 {
     puntos = puntos + 1;
     Debug.Log (puntos);
 }

The problem is that every time a new train collide whit a new house, the score return to 0, so the score its always 1. Sorry for my english, and also for my code, im new in unity.

Thanks :)