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:
| Region | Start datum | Target datum | c_x ( Metre ) | c_y (Metre) | c_z (Metre) | s ( ppm ) | r x ( Arcsecond ) | r y ( Arcsecond ) | r z ( Arcsecond ) |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Slovenia ETRS89 | D48 | D96 | 409.545 | 72.164 | 486.872 | 17.919665 | −3.085957 | −5.469110 | 11.020289 |
| England , Scotland , Wales | WGS84 | OSGB36 | −446.448 | 125.157 | −542.06 | 20.4894 | −0.1502 | −0.247 | −0.8421 |
| Ireland | WGS84 | Ireland 1965 | −482.53 | 130.596 | −564.557 | −8.15 | 1.042 | 0.214 | 0.631 |
| Germany | WGS84 | DHDN | −591.28 | −81.35 | −396.39 | −9.82 | 1.4770 | −0.0736 | −1.4580 |
| Germany | WGS84 | Bessel 1841 | −582 | −105 | −414 | −8.3 | −1.04 | −0.35 | 3.08 |
| Germany | WGS84 | Krassovski 1940 | −24 | 123 | 94 | −1.1 | −0.02 | 0.26 | 0.13 |
| Austria (BEV) | WGS84 | MGI | −577.326 | −90.129 | −463.920 | −2.423 | 5.137 | 1.474 | 5.297 |
Question:
How many values of r z (arcsecond) correspond with a r y (arcsecond) value of −0.247?
Answer:
−0.8421