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:
| Tournament | 2000 | 1999 | 1998 | 1997 | 1996 | 1995 | 1994 | 1993 | 1992 | 1991 |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Australian Open | 2R | QF | 3R | QF | 2R | A | 1R | 2R | 4R | A |
| French Open | 2R | 1R | 3R | 3R | 1R | 2R | 1R | 1R | 1R | A |
| Wimbledon | 1R | 4R | 4R | 1R | 3R | 2R | 3R | 1R | 1R | A |
| US Open | 2R | 3R | 3R | 1R | 1R | 2R | 1R | 2R | 2R | 3R |
| Year End Ranking | 24 | 14 | 12 | 18 | 46 | 43 | 133 | 59 | 100 | 129 |
Question:
What is the 1991 when 1997 is 18?
Answer:
129.0