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:
| Name | 1989 | 1990 | 1991 | 1992 | 1993 | 1994 | 1995 | 1996 | 1997 | 1998 | 1999 | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | 2007 | 2008 | 2009 | 2010 | Career\nSR | Career\nWin-Loss |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Australian Open | A | A | 1R | A | 2R | 3R | 2R | 1R | A | 3R | 4R | 1R | 2R | 1R | 3R | 2R | 1R | QF | 3R | 2R | 3R | 1R | 0 / 18 | 22–18 |
| French Open | 1R | 2R | 4R | 1R | 1R | 3R | 1R | A | 1R | 3R | 1R | 2R | 4R | 2R | 2R | 3R | 1R | 1R | 1R | 2R | 1R | A | 0 / 20 | 17–20 |
| Wimbledon | A | 1R | A | A | A | A | 1R | A | 1R | A | 2R | 2R | 3R | 2R | 2R | 2R | 2R | 2R | 2R | 1R | 2R | A | 0 / 14 | 11–14 |
| US Open | A | 3R | 1R | 2R | 1R | A | 1R | A | 1R | 3R | 3R | 1R | 2R | 1R | 2R | 3R | 2R | 1R | 2R | 1R | 1R | A | 0 / 18 | 13–18 |
| Grand Slam SR | 0 / 1 | 0 / 3 | 0 / 3 | 0 / 2 | 0 / 3 | 0 / 2 | 0 / 4 | 0 / 1 | 0 / 3 | 0 / 3 | 0 / 4 | 0 / 4 | 0 / 4 | 0 / 4 | 0 / 4 | 0 / 4 | 0 / 4 | 0 / 4 | 0 / 4 | 0 / 4 | 0 / 4 | 0 / 1 | 0 / 70 | N/A |
| Grand Slam Win-Loss | 0–1 | 3–3 | 3–3 | 1–2 | 1–3 | 4–2 | 1–4 | 0–1 | 0–3 | 6–3 | 6–4 | 2–4 | 7–4 | 2–4 | 5–4 | 6–4 | 2–4 | 5–4 | 4–4 | 2–4 | 3–4 | 0–1 | N/A | 63–70 |
| Indian Wells | NME | A | 3R | 1R | QF | 3R | 2R | A | A | 1R | A | 3R | 2R | 3R | 1R | 1R | 4R | 1R | A | A | A | A | 0 / 13 | 16–13 |
| Miami | NME | 2R | 2R | 1R | 3R | A | A | A | A | 4R | 3R | 2R | 4R | 2R | A | 1R | A | 2R | 3R | 3R | 2R | A | 0 / 14 | 15–14 |
| Monte Carlo | NME | 1R | 2R | 2R | 1R | A | 3R | 3R | SF | QF | A | 2R | 1R | 1R | 1R | 3R | 2R | 1R | A | 1R | A | A | 0 / 16 | 17–16 |
| Rome | NME | A | QF | 3R | 3R | A | 3R | A | 2R | 1R | 3R | 3R | 2R | 1R | 1R | A | 2R | 3R | A | 1R | A | A | 0 / 14 | 18–14 |
| Hamburg | NME | 2R | A | A | A | A | 1R | A | A | QF | 2R | 1R | QF | 1R | 1R | A | 1R | 1R | A | A | NME | NME | 0 / 10 | 8–10 |
| Canada | NME | A | A | A | A | A | A | A | QF | 2R | QF | 1R | SF | QF | 1R | QF | 1R | 1R | A | A | A | A | 0 / 10 | 17–10 |
| Cincinnati | NME | A | A | A | A | A | A | A | 2R | 1R | 2R | QF | 2R | 1R | 2R | QF | 2R | 1R | A | A | A | A | 0 / 10 | 11–10 |
| Stuttgart/Madrid | NME | A | A | A | A | A | A | A | 3R | 1R | 2R | 2R | 1R | SF | A | A | A | A | 1R | A | A | A | 0 / 7 | 8–7 |
| Paris | NME | 1R | 1R | 1R | A | A | A | A | 2R | 2R | 2R | QF | 2R | 1R | 2R | A | 2R | 1R | 3R | A | 1R | A | 0 / 14 | 10–14 |
| Masters Series SR | N/A | 0 / 4 | 0 / 5 | 0 / 5 | 0 / 4 | 0 / 1 | 0 / 4 | 0 / 1 | 0 / 6 | 0 / 9 | 0 / 7 | 0 / 9 | 0 / 9 | 0 / 9 | 0 / 7 | 0 / 5 | 0 / 7 | 0 / 8 | 0 / 3 | 0 / 3 | 0 / 2 | 0 / 0 | 0 / 108 | N/A |
| Annual Win-Loss | N/A | 2–4 | 7–5 | 3–5 | 6–4 | 2–1 | 5–4 | 2–1 | 12–6 | 10–9 | 10–7 | 12–9 | 13–9 | 9–9 | 2–7 | 8–5 | 7–7 | 3–8 | 4–3 | 2–3 | 1–2 | 0–0 | N/A | 120–108 |
| Year End Ranking | 235 | 62 | 43 | 43 | 55 | 46 | 102 | 118 | 29 | 41 | 34 | 31 | 22 | 35 | 62 | 52 | 58 | 52 | 37 | 52 | 68 | – | N/A |  |
Question:
how many grand slam events are there?
Answer:
4