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:
| Antibody | Brand name | Approval date | Type | Target | Approved treatment(s) |
| --- | --- | --- | --- | --- | --- |
| Alemtuzumab | Campath | 2001.0 | humanized | CD52 | Chronic lymphocytic leukemia |
| Bevacizumab | Avastin | 2004.0 | humanized | vascular endothelial growth factor | colorectal cancer |
| Brentuximab vedotin | Adcetris | 2011.0 | chimeric | CD30 | Hodgkin lymphoma , Anaplastic large-cell lymphoma |
| Cetuximab | Erbitux | 2004.0 | chimeric | epidermal growth factor receptor | colorectal cancer |
| Gemtuzumab ozogamicin | Mylotarg | 2000.0 | humanized | CD33 | acute myelogenous leukemia (with calicheamicin ) |
| Panitumumab | Vectibix | 2006.0 | human | epidermal growth factor receptor | colorectal cancer |
| Rituximab | Rituxan, Mabthera | 1997.0 | chimeric | CD20 | non-Hodgkin lymphoma |
Question:
How many targets are there with an approval date of 1997?
Answer:
1.0