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:
| Date | Opponent | Score | Loss | Attendance | Series | Arena |
| --- | --- | --- | --- | --- | --- | --- |
| May 19 | Oilers | 3–1 | Bryzgalov (6–2) | 17174.0 | 0–1 | Arrowhead Pond of Anaheim |
| May 21 | Oilers | 3–1 | Bryzgalov (6–3) | 17264.0 | 0–2 | Arrowhead Pond of Anaheim |
| May 23 | @ Oilers | 5–4 | Bryzgalov (6–4) | 16839.0 | 0–3 | Rexall Place |
| May 25 | @ Oilers | 6–3 | Roloson (11–5) | 16839.0 | 1–3 | Rexall Place |
| May 27 | Oilers | 2–1 | Giguere (3–3) | 17174.0 | 1–4 | Arrowhead Pond of Anaheim |
Question:
What was the attendance on may 21?
Answer:
17264.0