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:
| AIRLINES | IATA | ICAO | CALLSIGN | COMMENCED OPERATIONS |
| --- | --- | --- | --- | --- |
| Jetstar Asia Airways | 3K | JSA | JETSTAR ASIA | 2004.0 |
| Scoot | TZ | SCO | SCOOTER | 2012.0 |
| SilkAir | MI | SLK | SILKAIR | 1976.0 |
| Singapore Airlines | SQ | SIA | SINGAPORE | 1947.0 |
| Singapore Airlines Cargo | SQ | SQC | SINGCARGO | 2001.0 |
| Tigerair | TR | TGW | GO CAT | 2003.0 |
| Valuair | VF | VLU | VALUAIR | 2004.0 |
Question:
Who is the call sign that has a commenced operation before 1976?
Answer:
SINGAPORE