How to add a new row to csv file every second

Hello! I would like to know how I can add a new row to a csv file at every second or every 0.1 second. This would be helpful for my research in VR since I need to determine the headset position/rotation with respect to time when in play mode.

I developed the following code below to write the CSV file, however, it does not add new rows to the file at every second:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using System.IO; // Library that allows us to write to files
 
 public class CSVWriter : MonoBehaviour
 {
     public float timer = 0.0f;
     public float seconds = 0.0f;
 
     private float xPos;
     private float yPos;
     private float zPos;
 
     private float xRot;
     private float yRot;
     private float zRot;
 
     string fileName = ""; // variable to store file name (declared in start())
 
     [System.Serializable]
 
     public class Player
     {
         public string ID;
         public string name;
         public string gender;
         public string age;
     }
 
     [System.Serializable]
 
     public class PlayerList
     {
         public Player[] player;
     }
 
     public PlayerList myPlayerList = new PlayerList();
 
     // Start is called before the first frame update
     void Start()
     {
         fileName = Application.dataPath + "/DataCollection.csv";
     }
 
     // Update is called once per frame
     void Update()
     {
         WriteCSV();
         timer += Time.deltaTime;
         seconds = Mathf.Round(timer);
     }
 
     public void WriteCSV()
     {
         if(myPlayerList.player.Length > 0) // check if there is a player in the player list
         {
             TextWriter tw = new StreamWriter(fileName, false); // opens the file and deletes everything prior
             tw.WriteLine("ID, Name, Gender, Age, Time, xPos, yPos, zPos, xRot, yRot, zRot"); // write the headings ("," adds a column)
             tw.Close();
 
             tw = new StreamWriter(fileName, true); // reopen the file and append
 
             for(seconds = 0; seconds < 60; seconds++) // for every second, add the following data to the file
             {
                 tw.WriteLine(myPlayerList.player[0].ID + "," + myPlayerList.player[0].name + "," + myPlayerList.player[0].gender + "," + myPlayerList.player[0].age + "," + seconds);
             }
 
             tw.Close();
         }
     }
 }
 

Also, how can I export the VR headset position & rotation with respect to time to the same csv file? It would be highly helpful if someone can support me in this since I am very new to unity and coding. Thank you!