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:
| Election | Party name | Total votes | Share of votes | Seats | Share of seats | Party Leader(s) | Notes |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 1961 | Progressive Party | 69,045 | 8.6% | 1 | 0.6% | Jan Steytler | National Party (NP) victory |
| 1966 | Progressive Party | 39,717 | 3.1% | 1 | 0.6% | Jan Steytler | NP victory |
| 1970 | Progressive Party | 51,760 | 3.5% | 1 | 0.6% | Jan Steytler | NP victory |
| 1974 | Progressive Party | 58,768 | 5.3% | 7 | 4.1% | Colin Eglin | NP victory |
| 1977 | Progressive Federal Party | 177,705 | 16.7% | 17 | 10.3% | Colin Eglin | NP victory; PFP gains official opposition status from United Party |
| 1981 | Progressive Federal Party | 265,297 | 19.4% | 27 | 15.2% | Frederik van Zyl Slabbert | NP victory; PFP remains official opposition |
| 1987 | Progressive Federal Party | 288,579 | 13.9% | 20 | 11.2% | Colin Eglin | NP victory; PFP loses official opposition status to Conservative Party |
| 1989 | Democratic Party | 431,444 | 20.0% | 34 | 19.1% | Zach de Beer, Denis Worrall and Wynand Malan | NP victory |
Question:
in how many years did the listed party have at least 10.0% share of votes?
Answer:
4