C# Employee Pay Data using JSON file

I’m looking for some feedback on my code here. I want to eliminate duplicating the code through the different button_clicks. I’m thinking with a method but nothing I try works better than what I have.

using System; using System.Collections.Generic; using System.Data; using System.IO; using System.Linq; using System.Windows.Forms; using Newtonsoft.Json; using Newtonsoft.Json.Linq;  namespace EmployeePayDataWk4 { public partial class Employee_Pay_Form : Form {             public Employee_Pay_Form()     {         InitializeComponent();                 }      private void Employee_Pay_Form_Load(object sender, EventArgs e)     {         EmployeeDataGridView.ColumnCount = 8;         EmployeeDataGridView.Columns[0].Name = "Employee Name";         EmployeeDataGridView.Columns[1].Name = "Zip Code";         EmployeeDataGridView.Columns[2].Name = "Age";         EmployeeDataGridView.Columns[3].Name = "Monthly Gross Pay";         EmployeeDataGridView.Columns[4].Name = "Department ID";         EmployeeDataGridView.Columns[5].Name = "Developer Type";         EmployeeDataGridView.Columns[6].Name = "Annual Taxes";         EmployeeDataGridView.Columns[7].Name = "Annual Net Pay";                  }      private void LoadAllButton_Click(object sender, EventArgs e)     {         EmployeeDataGridView.Rows.Clear();         //Read from JSON file         string JSONstring = File.ReadAllText("JSON.json");         List<Employee> employees = JsonConvert.DeserializeObject<List<Employee>>(JSONstring);          //Display into DataGridView         foreach (Employee emp in employees)         {             string[] row = { emp.Name, emp.Zip, emp.Age.ToString(), string.Format("{0:C}", emp.Pay),                 emp.DepartmentId.ToString(), SetDevType(emp.DepartmentId),                 string.Format("{0:C}", emp.CalculateTax(emp.Pay)),                 string.Format("{0:C}", AnnualPay(emp.Pay) - emp.CalculateTax(emp.Pay))};             EmployeeDataGridView.Rows.Add(row);         }     }        private void FTEmployeeButton_Click(object sender, EventArgs e)     {         EmployeeDataGridView.Rows.Clear();          //Read from JSON file         string JSONstring = File.ReadAllText("JSON.json");         List<Employee> employees = JsonConvert.DeserializeObject<List<Employee>>(JSONstring);          //LINQ Query for FT Employees         var FTEmp = from emp in employees                     where emp.GetTaxForm == "W2"                     select emp;          //Display into DataGridView         foreach (Employee emp in FTEmp)         {             string[] row = { emp.Name, emp.Zip, emp.Age.ToString(), string.Format("{0:C}", emp.Pay),                 emp.DepartmentId.ToString(), SetDevType(emp.DepartmentId),                 string.Format("{0:C}", emp.CalculateTax(emp.Pay)),                 string.Format("{0:C}", AnnualPay(emp.Pay) - emp.CalculateTax(emp.Pay))};             EmployeeDataGridView.Rows.Add(row);         }     }      private void ContractEmployeeButton_Click(object sender, EventArgs e)     {         EmployeeDataGridView.Rows.Clear();          //Read from JSON file         string JSONstring = File.ReadAllText("JSON.json");         List<Employee> employees = JsonConvert.DeserializeObject<List<Employee>>(JSONstring);          //LINQ Query for Contract Employees         var contractEmp = from emp in employees                           where emp.GetTaxForm == "1099"                           select emp;          //Display into DataGridView         foreach (Employee emp in contractEmp)         {             string[] row = { emp.Name, emp.Zip, emp.Age.ToString(), string.Format("{0:C}", emp.Pay),                 emp.DepartmentId.ToString(), SetDevType(emp.DepartmentId),                 string.Format("{0:C}", emp.CalculateTax(emp.Pay)),                 string.Format("{0:C}", AnnualPay(emp.Pay) - emp.CalculateTax(emp.Pay))};             EmployeeDataGridView.Rows.Add(row);         }     }       //Method to determine developer type     string typeName;     public string SetDevType(int id)     {         if (id == 1)         {             typeName = "Object-Oriented";         }         else if (id == 2)         {             typeName = "Scripts";         }         else { typeName = "Unknown"; }         return typeName;     }      public double AnnualPay(double amount) => 12 * amount; }   class Employee : IFilingStatus {     public Employee() { }      public string Name { get; set; }     public string Zip { get; set; }     public int Age { get; set; }     public double Pay { get; set; }     public int DepartmentId { get; set; }       public string GetTaxForm { get; set; }      public double CalculateTax(double basis)     {         double monthlyTax;           if ((GetTaxForm == "W2") || (GetTaxForm == "w2"))         {             monthlyTax = .07 * basis;         }         else         {             monthlyTax = 0;         }         return 12 * monthlyTax;     }     public double AnnualPay(double amount) => 12 * amount; }  public interface IFilingStatus {     double CalculateTax(double basis); }  }