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 | 1984 | 1985 | 1986 | 1987 | 1988 | 1989 | 1990 | 1991 | 1992 | 1993 | 1994 | 1995 | 1996 | Career SR |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Grand Slams | Grand Slams | Grand Slams | Grand Slams | Grand Slams | Grand Slams | Grand Slams | Grand Slams | Grand Slams | Grand Slams | Grand Slams | Grand Slams | Grand Slams | Grand Slams | Grand Slams |
| Australian Open | A | A | NH | A | A | A | 3R | 1R | 2R | A | 3R | 4R | A | 0 / 5 |
| French Open | 3R | 1R | 1R | QF | 1R | 3R | 4R | 1R | 1R | QF | 1R | 1R | A | 0 / 12 |
| Wimbledon | A | A | 1R | 1R | 2R | 2R | 3R | 4R | 1R | 1R | 1R | 1R | A | 0 / 10 |
| US Open | A | A | 1R | 1R | A | A | 1R | 3R | A | 3R | SF | 1R | A | 0 / 7 |
| Grand Slam SR | 0 / 1 | 0 / 1 | 0 / 3 | 0 / 3 | 0 / 2 | 0 / 2 | 0 / 4 | 0 / 4 | 0 / 3 | 0 / 3 | 0 / 4 | 0 / 4 | 0 / 0 | 0 / 34 |
| ATP Masters Series | ATP Masters Series | ATP Masters Series | ATP Masters Series | ATP Masters Series | ATP Masters Series | ATP Masters Series | ATP Masters Series | ATP Masters Series | ATP Masters Series | ATP Masters Series | ATP Masters Series | ATP Masters Series | ATP Masters Series | ATP Masters Series |
| Indian Wells | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | 1R | A | 3R | A | A | 1R | A | 0 / 3 |
| Key Biscayne | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | 2R | 2R | 2R | A | A | 2R | 1R | 0 / 5 |
| Monte Carlo | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | 2R | 1R | 3R | 1R | 1R | 2R | A | 0 / 6 |
| Rome | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | 2R | 1R | 1R | 3R | 1R | 1R | A | 0 / 6 |
| Hamburg | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | 1R | W | QF | 3R | 1R | A | A | 0 / 5 |
| Canada | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | A | A | A | A | A | A | A | 0 / 0 |
| Cincinnati | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | 1R | A | A | A | 1R | A | A | 0 / 2 |
| Stuttgart (Stockholm) | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | 2R | 3R | 3R | A | A | A | A | 0 / 3 |
| Paris | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | Not MS1 Before 1990 | 1R | QF | 1R | 3R | A | A | A | 0 / 4 |
| Masters Series SR | N/A | N/A | N/A | N/A | N/A | N/A | 0 / 8 | 1 / 6 | 0 / 7 | 0 / 4 | 0 / 4 | 0 / 4 | 0 / 1 | 0 / 34 |
| Year End Ranking | 138 | 159 | 33 | 76 | 127 | 74 | 34 | 8 | 23 | 17 | 28 | 121 | 409 | N/A |
Question:
What is the 1991 when 1990 is ATP Masters Series?
Answer:
ATP Masters Series