Web scraping xpath is returning null

See more:

C#

ASP.NET

XPath

webscraping

Hello,

I am performing web scraping but xpath returns null.
I am trying this since yesterday and when i ran my code in the morning today it returned me unformatted result i am not sure how because since then it is returning null value again. I do not know what the problem is. I would highly appreciate your help. Below is my code.

private async Task<List<NameAndScore>> WebDateFromPage(int pagenum)
       {
           string url = "http://www.realtor.com/realestateagents/New-York_NY/photo-1";
 

           if (pagenum != 0)
               url = "http://www.realtor.com/realestateagents/New-York_NY/photo-1/pg-" + pagenum.ToString();
 
           var doc = await Task.Factory.StartNew(() => web.Load(url));
 

           //var nameNodes = doc.DocumentNode.SelectNodes("//*[@id=\"agent_list_wrapper\"]/div[2]/div[2]/div/div[1]/a");
           //var scoreNodes = doc.DocumentNode.SelectNodes("//*[@id=\"agent_list_wrapper\"]//div//div//div//div//span");

           var nameNodes = doc.DocumentNode.SelectNodes("//*[@id=\"agent_list_wrapper\"]//div//div//div/div//a");
           var scoreNodes = doc.DocumentNode.SelectNodes("//*[@id=\"agent_list_wrapper\"]//div//div//div//div");
 
           if (nameNodes == null || scoreNodes == null)
               return new List<NameAndScore>();
 
           var names = nameNodes.Select(node => node.InnerText);
           var scores = scoreNodes.Select(node => node.InnerText);
 
           return names.Zip(scores, (name, score) => new NameAndScore() { Name = name, Score = score }).ToList();
       }
 
        private async void Form1_Load(object sender, EventArgs e)
       {
           int pagenum = 0;
           var rankings = await WebDateFromPage(0);
           while (rankings.Count > 0)
           {
               foreach (var ranking in rankings)
                   table.Rows.Add(ranking.Name, ranking.Score);
               pagenum = pagenum + 1;
               rankings = await WebDateFromPage(pagenum);
           }
 
       }

What I have tried:

I have tried every possible combination of XPATH. Tried to copy different tags of XPATH of the attached website but it returns null every time. I do not what the problem is as it returned value just once