Using HTMLAgility pack to extract value from a Xpath using c# console app

I have the following line of HTML code and I used google chrome for xpath.

<DIV id=TasheelPaymentCtrl1_dvPayment>
<TABLE border=1 cellSpacing=0 borderColor=black cellPadding=7 width=625 align=center>
<TBODY>
<TR>
<TD class=ReceiptHeadArbCenterHead1 width=320>المسمى </TD>
<TD class=ReceiptHeadArbCenterHead1 width=75>دفع إلى</TD>
<TD class=ReceiptHeadArbCenterHead1 width=75>القيمة</TD>
<TD class=ReceiptHeadArbCenterHead1 width=75>الكمية</TD>
<TD class=ReceiptHeadArbCenterHead1 width=75>المجموع</TD></TR>
<TR>
<TD class=ReceiptHeadArbCenterHead>رسوم وزارة العمل</TD>
<TD class=ReceiptValueArbCenter>MOFI</TD>
<TD class=ReceiptValueArbCenter>3</TD>
<TD class=ReceiptValueArbCenter>1</TD>
<TD class=ReceiptValueArbCenter>3</TD>
<TR>
<TD class=ReceiptHeadArbCenterHead>رسوم الدرهم الإلكتروني</TD>
<TD class=ReceiptValueArbCenter>MOFI</TD>
<TD class=ReceiptValueArbCenter>3</TD>
<TD class=ReceiptValueArbCenter>1</TD>
<TD class=ReceiptValueArbCenter>3</TD>
<TR>
<TD class=ReceiptHeadArbCenterHead>رسوم مراكز الخدمة </TD>
<TD class=ReceiptValueArbCenter>MOFI</TD>
<TD class=ReceiptValueArbCenter>47</TD>
<TD class=ReceiptValueArbCenter>1</TD>
<TD class=ReceiptValueArbCenter>47</TD>
<TR>
<TD class=ReceiptHeadArbCenterHead1 colSpan=4>المجموع</TD>
<TD class=ReceiptValueArbCenter>53</TD></TR></TBODY></TABLE></DIV>

I want to extract values 3, 3, 47 and 53

I tried using this xpath

 var gf = doc.DocumentNode.SelectNodes("//div[@id='TasheelPaymentCtrl1_dvPayment']/table/tbody/tr[2]/td[5]");

                foreach (var node in gf)
                {


                    Console.WriteLine(node.InnerText); //output: "3"
                }

                var sf = doc.DocumentNode.SelectNodes("//div[@id='TasheelPaymentCtrl1_dvPayment']/table/tbody/tr[3]/td[5]");

                foreach (var node in sf)
                {


                    Console.WriteLine(node.InnerText); //output: "3"
                }
                var tf = doc.DocumentNode.SelectNodes("//div[@id='TasheelPaymentCtrl1_dvPayment']/table/tbody/tr[4]/td[5]");

                foreach (var node in tf)
                {


                    Console.WriteLine(node.InnerText); //output: "47"
                }
var Allf = doc.DocumentNode.SelectNodes("//div[@id='TasheelPaymentCtrl1_dvPayment']/table/tbody/tr[5]/td[2]");

                foreach (var node in Allf )
                {


                    Console.WriteLine(node.InnerText); //output: "53"
                }

but i am getting null object exception.. I used Google chrome developer tools to copy the xpath. I am getting null point exception . How can extract value .. My question is why I am getting null point reference exception, is there any mistake in xpath value? Please help me.