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:
| Denomination | 1870 | 1880 | 1890 | 1900 | 1910 | 1920 | 1930 | 1941 | 1949 | 2001 | 2011 |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Roman Catholic | 72.3% | 69.4% | 64.7% | 60.7% | 59.8% | 59.1% | 60.7% | 63.1% | 69.8% | 45.8% | 28.9% |
| Calvinist | 4.8% | 6.1% | 7.4% | 8.9% | 9.9% | 10.9% | 12.1% | 13.6% | 15.5% | 12.6% | 8.5% |
| Lutheran | 5.3% | 5.5% | 5.6% | 5.3% | 4.9% | 4.8% | 5% | 5.3% | 5.4% | 2.6% | 1.7% |
| Jewish | 16.6% | 19.7% | 21% | 23.6% | 23.1% | 23.2% | 20.3% | 15.8% | 6.4% | 0.5% | 0.4% |
| Others | 1% | 1.3% | 1.3% | 1.5% | 2.2% | 2% | 1.9% | 1.6% | 1.4% | 3.9% | 3.5% |
| Without religion | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 19.5% | 22.9% |
| No answer | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 15.1% | 34.1% |
Question:
how many denominations never dropped below 20%?
Answer:
1