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:
| Class | Operator | No. Built | Year Built | Cars per Set |
| --- | --- | --- | --- | --- |
| Class 153 | Arriva Trains Wales | 70.0 | 1991–1992 | 1.0 |
| Class 153 | East Midlands Trains | 70.0 | 1991–1992 | 1.0 |
| Class 153 | London Midland | 70.0 | 1991–1992 | 1.0 |
| Class 153 | Greater Anglia | 70.0 | 1991–1992 | 1.0 |
| Class 153 | Northern Rail | 70.0 | 1991–1992 | 1.0 |
| Class 153 | First Great Western | 70.0 | 1991–1992 | 1.0 |
Question:
Tell me the sum of cars per set for operator of london midland
Answer:
1.0