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:
| Landfill | Location | Acres | Opened | Capacity | Status | Rehab Period |
| --- | --- | --- | --- | --- | --- | --- |
| Gin Drinkers Bay | Kwai Tsing District | 29.0 | 1960.0 | 3.5 million tonnes | Closed | 1999–2000 |
| Ngau Tam Mei | Yuen Long District | 2.0 | 1973.0 | 0.15 million tonnes | Closed | 1999–2000 |
| Shuen Wan | Tai Po District | 50.0 | 1973.0 | 15 million tonnes | Closed | 1996–1997 |
| Ma Tso Lung | North District | 2.0 | 1976.0 | 0.2 million tonnes | Closed | 1999–2000 |
| Ngau Chi Wan | Wong Tai Sin District | 8.0 | 1976.0 | 0.7 million tonnes | Closed | 1997–1998 |
| Sai Tso Wan | Kwun Tong District | 9.0 | 1978.0 | 1.6 million tonnes | Closed | 1997–1998 |
| Siu Lang Shui | Tuen Mun District | 12.0 | 1978.0 | 1.2 million tonnes | Closed | 1999–2000 |
| Tseung Kwan O Stage I | Sai Kung District | 68.0 | 1978.0 | 15.2 million tonnes | Closed | 1997–1999 |
| Ma Yau Tong West | Kwun Tong | 6.0 | 1979.0 | 6 million tonnes | Closed | 1997–1998 |
| Ma Yau Tong Central | Kwun Tong | 11.0 | 1981.0 | 1.0 million tonnes | Closed | 1997–1998 |
| Pillar Point Valley | Tuen Mun District | 38.0 | 1983.0 | 13 million tonnes | Closed | 2004–2006 |
| Jordan Valley | Kwun Tong | 11.0 | 1986.0 | 1.5 million tonnes | Closed | 1997–1998 |
| Tseung Kwan O Stage II-III | Sai Kung District | 42.0 | 1988.0 | 12.6 million tonnes | Closed | 1997–1999 |
Question:
What is the total number of acres at Sai Tso Wan, opening before 1978?
Answer:
0.0