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:
| Year | Competition | Location | Event | Final-Rank | Final-Score | Qualifying Rank | Qualifying Score |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 2008 | 2008 Summer Olympics | Beijing | Team | 2 | 186.525 | 2 | 246.800 |
| 2008 | 2008 Summer Olympics | Beijing | Uneven Bars | DNQ | N/A | 23 | 14.800 |
| 2008 | Olympic Trials | Philadelphia | All Around | 4 | 61.850 | 4 | 61.400 |
| 2008 | Olympic Trials | Philadelphia | Balance Beam | 4 | 15.550 | 4 | 15.800 |
| 2008 | Olympic Trials | Philadelphia | Floor Exercise | 2 | 15.500 | 3 | 15.650 |
| 2008 | Olympic Trials | Philadelphia | Uneven Bars | 6 | 15.200 | 5 | 15.300 |
| 2008 | Olympic Trials | Philadelphia | Vault | 4 | 15.150 | 3 | 15.100 |
| 2008 | U.S. Championships | Boston | All Around | 4 | 61.250 | 4 | 60.750 |
| 2008 | U.S. Championships | Boston | Balance beam | 5 | 16.000 | 5 | 15.400 |
| 2008 | U.S. Championships | Boston | Floor Exercise | 10 | 14.750 | 4 | 15.200 |
| 2008 | U.S. Championships | Boston | Uneven Bars | 6 | 15.550 | 6 | 15.150 |
| 2008 | American Cup | New York City | All Around | 3 | 63.075 | 3 | 63.075 |
Question:
what was the difference between her qualifying scores for balance beam between boston and philadelphia?
Answer:
0.400