Please read the following table in HTML format from a webpage and then answer the question in detail according to the table. Each table cell is defined by a <td> and a </td> tag. Each table row starts with a <tr> and ends with a </tr> tag. 'rowspan=m' and 'colspan=n' represents a cell spaning over 'm' rows and 'n' columns.

Webpage title:
Upstairs Downstairs (2010 TV series)
Table title:
Series 2 (2012)
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > Series No. </th><th colspan=1 rowspan=1 > Episode No. </th><th colspan=1 rowspan=1 > Title </th><th colspan=1 rowspan=1 > Directed by </th><th colspan=1 rowspan=1 > Written by </th><th colspan=1 rowspan=1 > Original air date </th><th colspan=1 rowspan=1 > UK viewers (million) </th></tr>
<tr> <th colspan=1 rowspan=1 > 4 </th><td class="highlighted"  colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > "A Faraway Country About Which We Know Nothing" </td><td colspan=1 rowspan=1 > Marc Jobst </td><td colspan=1 rowspan=1 > Heidi Thomas </td><td class="highlighted"  colspan=1 rowspan=1 > 19 February 2012 </td><td colspan=1 rowspan=1 > 7.87 </td></tr>
<tr> <td colspan=8 rowspan=1 > September 1938. Hallam's concerns over Germany lead to an unexpected encounter. </td></tr>
<tr> <th colspan=1 rowspan=1 > 5 </th><td class="highlighted"  colspan=1 rowspan=1 > 2 </td><td colspan=1 rowspan=1 > "The Love That Pays the Price" </td><td colspan=1 rowspan=1 > Marc Jobst </td><td colspan=1 rowspan=1 > Heidi Thomas </td><td colspan=1 rowspan=1 > 26 February 2012 </td><td colspan=1 rowspan=1 > 6.70 </td></tr>
<tr> <td colspan=8 rowspan=1 > November 1938. Agnes is told she can have no more children, and distracts herself by throwing a dinner party where she and Hallam meet American millionaire Caspar Landry. </td></tr>
<tr> <th colspan=1 rowspan=1 > 6 </th><td class="highlighted"  colspan=1 rowspan=1 > 3 </td><td colspan=1 rowspan=1 > "A Perfect Specimen of Womanhood" </td><td colspan=1 rowspan=1 > Anthony Byrne </td><td colspan=1 rowspan=1 > Heidi Thomas </td><td colspan=1 rowspan=1 > 4 March 2012 </td><td colspan=1 rowspan=1 > 5.86 </td></tr>
<tr> <td colspan=8 rowspan=1 > January 1939. The house is rocked by controversy when the publication of a scandalous novel exposes Blanche's unconventional lifestyle, bringing her face to face with the author of the book—her former lover, Lady Portia Alresford. </td></tr>
<tr> <th colspan=1 rowspan=1 > 7 </th><td class="highlighted"  colspan=1 rowspan=1 > 4 </td><td colspan=1 rowspan=1 > "All the Things You Are" </td><td colspan=1 rowspan=1 > Brendan Maher </td><td colspan=1 rowspan=1 > Steve Thompson </td><td colspan=1 rowspan=1 > 11 March 2012 </td><td colspan=1 rowspan=1 > 5.51 </td></tr>
<tr> <td colspan=8 rowspan=1 > March 1939. Harry signs up for a boxing tournament to impress Beryl, only to be told he is too old for the ring, so he recruits Johnny as his protégé. </td></tr>
<tr> <th colspan=1 rowspan=1 > 8 </th><td class="highlighted"  colspan=1 rowspan=1 > 5 </td><td colspan=1 rowspan=1 > "The Last Waltz" </td><td colspan=1 rowspan=1 > Brendan Maher </td><td colspan=1 rowspan=1 > Debbie O'Malley </td><td colspan=1 rowspan=1 > 18 March 2012 </td><td colspan=1 rowspan=1 > 5.56 </td></tr>
<tr> <td colspan=8 rowspan=1 > July & August 1939. Matters of the heart concern the masters and staff of Eaton Place, as Mr Pritchard finds romance at the annual servants' ball, prompting him to wonder if there is more to life than service. </td></tr>
<tr> <th colspan=1 rowspan=1 > 9 </th><td class="highlighted"  colspan=1 rowspan=1 > 6 </td><td colspan=1 rowspan=1 > "Somewhere Over the Rainbow" </td><td colspan=1 rowspan=1 > Anthony Byrne </td><td colspan=1 rowspan=1 > Heidi Thomas </td><td class="highlighted"  colspan=1 rowspan=1 > 25 March 2012 </td><td class="highlighted"  colspan=1 rowspan=1 > 5.22 </td></tr>
<tr> <td colspan=8 rowspan=1 > August & September 1939. Lady Agnes returns home, desperate to heal the rift in her marriage, and Sir Hallam is more than willing to make amends for his part in their troubles. </td></tr>
</table>
Question:
When did the second series of Upstairs Downstairs run on TV?
Answer:
The second series of Upstairs Downstairs had six episodes which began on 19 February 2012 and ended on 25 March with 5.22 million viewers.