private void btnAverageSalEmp_Click(object sender, EventArgs e)
        {
           IEnumerable<decimal> dec = employeeList.Select(s => s.YearlySalary);
           decimal avg = dec.Average();
           MessageBox.Show("Average of all Employee Salary: " + avg.ToString());
        }

        private void button2_Click(object sender, EventArgs e)
        {
            IEnumerable<decimal> companyNameQuery = from emp in employeeList where emp.CompanyName == cboCompany.Text select emp.YearlySalary;
            decimal avg = companyNameQuery.Average();
            MessageBox.Show("Average of Employee Salary based on Company Selected: " + avg.ToString("c"));
        }

        private void btnDisplayOverAvgSalary_Click(object sender, EventArgs e)
        {
            IEnumerable<decimal> dec = employeeList.Select(s => s.YearlySalary);
            decimal avg = dec.Average();
            var names = employeeList.Select(s => new { FN = s.Firstname, LN = s.Lastname, CN = s.CompanyName, SAL = s.YearlySalary });
            foreach (var n in names)
            {
                if (n.SAL > avg)
                {
                    ListViewItem lstviewitem = new ListViewItem(n.FN);
                    lstviewitem.SubItems.Add(n.LN);
                    lstviewitem.SubItems.Add(n.CN);
                    lstviewitem.SubItems.Add(n.SAL.ToString("c"));
                    listView1.Items.Add(lstviewitem);
                }
            }

        }