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:
| Issued | Type | Design | Serial format | Serials issued |
| --- | --- | --- | --- | --- |
| 1973- 1974 | Passenger | yellow on blue | AB-12-34 | AA-00-00 to ZZ-99-99 |
| 1974 | Passenger | yellow on blue | 12-34-56 | 00-00-00 to unknown |
| 1975- 1976 | Passenger | black on yellow | ABC-123 | unknown |
| 1977- 1980 | Passenger | black on yellow | ABC-123 | unknown |
| 1981 | Passenger | black on yellow | ABC-123 | unknown |
| 1982 | Passenger | black on yellow | ABC-123 | unknown |
| 1983- 1984 | Passenger | black on yellow | ABC-123 | EAA-000 to EZZ-999 |
Question:
Which design has a serial format of AB-12-34?
Answer:
yellow on blue