Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Serial No. | District | Headquartered City | City Population (2009) | City Area(km 2 ) |
| --- | --- | --- | --- | --- |
| 1.0 | Attock District | Attock City | 94620.0 | 20.0 |
| 2.0 | Bahawalnagar District | Bahawalnagar City | 134936.0 | 13.0 |
| 3.0 | Bahawalpur District | Bahawalpur City | 530438.0 | 38.0 |
| 4.0 | Bhakkar District | Bhakkar City | 89380.0 | 15.0 |
| 5.0 | Chakwal District | Chakwal City | 113524.0 | 10.0 |
| 6.0 | Chiniot District | Chiniot City | 219254.0 | 12.0 |
| 7.0 | Dera Ghazi Khan District | Dera Ghazi Khan City | 464742.0 | 22.0 |
| 8.0 | Faisalabad District | Faisalabad City | 2793721.0 | 147.0 |
| 9.0 | Gujranwala District | Gujranwala City | 1526168.0 | 75.0 |
| 10.0 | Gujrat District | Gujrat City | 328512.0 | 25.0 |
| 11.0 | Hafizabad District | Hafizabad City | 165936.0 | 10.0 |
| 12.0 | Jhang District | Jhang City | 365198.0 | 28.0 |
| 13.0 | Jhelum District | Jhelum City | 172073.0 | 22.0 |
| 14.0 | Kasur District | Kasur City | 314617.0 | 18.0 |
| 15.0 | Khanewal District | Khanewal City | 165038.0 | 17.0 |
| 16.0 | Khushab District | Jauharabad City | 38475.0 | 12.0 |
| 17.0 | Lahore District | Lahore City | 6936563.0 | 462.0 |
| 18.0 | Layyah District | Layyah City | 82734.0 | 10.0 |
| 19.0 | Lodhran District | Lodhran City | 93232.0 | 8.0 |
| 20.0 | Mandi Bahauddin District | Mandi Bahauddin City | 150980.0 | 9.0 |
| 21.0 | Mianwali District | Mianwali City | 93659.0 | 20.0 |
| 22.0 | Multan District | Multan City | 1566932.0 | 133.0 |
| 23.0 | Muzaffargarh District | Muzaffargarh City | 158597.0 | 15.0 |
| 24.0 | Nankana Sahib District | Nankana Sahib City | 60137.0 | 6.0 |
| 25.0 | Narowal District | Narowal City | 74417.0 | 7.0 |
| 26.0 | Okara District | Okara City | 232386.0 | 21.0 |
| 27.0 | Pakpattan District | Pakpattan City | 136510.0 | 14.0 |
| 28.0 | Rahim Yar Khan District | Rahim Yar Khan City | 340810.0 | 22.0 |
| 29.0 | Rajanpur District | Rajanpur City | 42986.0 | 6.0 |
| 30.0 | Rawalpindi District | Rawalpindi City | 1933933.0 | 110.0 |
| 31.0 | Sahiwal District | Sahiwal City | 247706.0 | 28.0 |
| 32.0 | Sargodha District | Sargodha City | 586922.0 | 50.0 |
| 33.0 | Sheikhupura District | Sheikhupura City | 411834.0 | 22.0 |
| 34.0 | Sialkot District | Sialkot City | 502721.0 | 42.0 |
| 35.0 | Toba Tek Singh District | Toba Tek Singh City | 74480.0 | 9.0 |
| 36.0 | Vehari District | Vehari City | 124513.0 | 12.0 |
Question:
What is the sum of the serial numbers for narowal city?
Answer:
25.0