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:
| State Rank by Revenue | Company Name | National Rank | Revenue ($billions) 2012 estimate | Headquarters City | Known for |
| --- | --- | --- | --- | --- | --- |
| 1.0 | Walmart | 2.0 | 469.2 | Bentonville | Retailing |
| 2.0 | Tyson Foods | 93.0 | 33.3 | Springdale | Poultry |
| 3.0 | Murphy Oil | 104.0 | 28.8 | El Dorado | Petroleum |
| 4.0 | Dillard's | 378.0 | 6.8 | Little Rock | Clothing/department store |
| 5.0 | Windstream | 414.0 | 6.2 | Little Rock | Communications |
Question:
What is the rank of the company known for retailing?
Answer:
1.0