/// <summary>
/// Raises the trigger exit event - if the collider is a tank then decrease the number of tanks in zone
/// </summary>
/// <param name="c">C.</param>
private void OnTriggerExit(Collider c)
{
TankHealth tankHealth = c.GetComponentInParent <TankHealth>();
if (tankHealth != null)
{
Decrement();
tankHealth.NullifySpawnPoint(this);
}
}