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:
Alcatraz (TV series)
Table title:
Episodes
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > 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 > Production code </th><th colspan=1 rowspan=1 > U.S. viewers (million) </th></tr>
<tr> <th class="highlighted"  colspan=1 rowspan=1 > 1 </th><td colspan=1 rowspan=1 > "Pilot" </td><td colspan=1 rowspan=1 > Danny Cannon </td><td colspan=1 rowspan=1 > Steven Lilien, Bryan Wynbrandt & Elizabeth Sarnoff </td><td colspan=1 rowspan=1 > January 16, 2012 </td><td colspan=1 rowspan=1 > 296790 </td><td class="highlighted"  colspan=1 rowspan=1 > 10.05 </td></tr>
<tr> <td colspan=7 rowspan=1 > Years after every prisoner on Alcatraz mysteriously vanished, FBI Agent Emerson Hauser and Detective Rebecca Madsen are drawn into the case of Jack Sylvane, who is on a killing spree. </td></tr>
<tr> <th colspan=1 rowspan=1 > 2 </th><td colspan=1 rowspan=1 > "Ernest Cobb" </td><td colspan=1 rowspan=1 > Jack Bender </td><td colspan=1 rowspan=1 > Alison Balian </td><td colspan=1 rowspan=1 > January 16, 2012 </td><td colspan=1 rowspan=1 > 2J6052 </td><td colspan=1 rowspan=1 > 10.05 </td></tr>
<tr> <td colspan=7 rowspan=1 > Ernest Cobb (Joe Egender), another Alcatraz prisoner, is now killing people using a sniper rifle. Madsen and Hauser try to stop him before he kills more, forcing them to try and deduce the motivation for his murder sprees. </td></tr>
<tr> <th colspan=1 rowspan=1 > 3 </th><td colspan=1 rowspan=1 > "Kit Nelson" </td><td colspan=1 rowspan=1 > Jack Bender </td><td colspan=1 rowspan=1 > Jennifer Johnson </td><td colspan=1 rowspan=1 > January 23, 2012 </td><td colspan=1 rowspan=1 > 2J6053 </td><td colspan=1 rowspan=1 > 9.03 </td></tr>
<tr> <td colspan=7 rowspan=1 > A child killer, who would kidnap his victims and return their bodies home, reappears from the past, spurring a manhunt. Dr. </td></tr>
<tr> <th colspan=1 rowspan=1 > 4 </th><td colspan=1 rowspan=1 > "Cal Sweeney" </td><td colspan=1 rowspan=1 > Brad Anderson </td><td colspan=1 rowspan=1 > Robert Hull </td><td colspan=1 rowspan=1 > January 30, 2012 </td><td colspan=1 rowspan=1 > 2J6055 </td><td colspan=1 rowspan=1 > 8.44 </td></tr>
<tr> <td colspan=7 rowspan=1 > A bank robber from the past causes mayhem in the present and puts Rebecca in a difficult position as she has to work out how to get him out of the bank without revealing the existence of the 63s. </td></tr>
<tr> <th colspan=1 rowspan=1 > 5 </th><td colspan=1 rowspan=1 > "Guy Hastings" </td><td colspan=1 rowspan=1 > Charles Beeson </td><td colspan=1 rowspan=1 > Steven Lilien & Bryan Wynbrandt </td><td colspan=1 rowspan=1 > February 6, 2012 </td><td colspan=1 rowspan=1 > 2J6056 </td><td colspan=1 rowspan=1 > 6.91 </td></tr>
<tr> <td colspan=7 rowspan=1 > A guard from Alcatraz appears- acting in a far more violent manner than the team would have expected- and encounters Ray, whom Rebecca suspects the guard may be using to track down her grandfather. </td></tr>
<tr> <th colspan=1 rowspan=1 > 6 </th><td colspan=1 rowspan=1 > "Paxton Petty" </td><td colspan=1 rowspan=1 > Paul Edwards </td><td colspan=1 rowspan=1 > Teleplay by: Steven Lilien, Bryan Wynbrandt & Robert Hull Story by: Jennifer Johnson </td><td colspan=1 rowspan=1 > February 13, 2012 </td><td colspan=1 rowspan=1 > 2J6058 </td><td colspan=1 rowspan=1 > 6.24 </td></tr>
<tr> <td colspan=7 rowspan=1 > A military land mine specialist resurfaces and plants bombs throughout the city. Rebecca, Soto and Hauser follow a series of clues to find his next targeted location. </td></tr>
<tr> <th colspan=1 rowspan=1 > 7 </th><td colspan=1 rowspan=1 > "Johnny McKee" </td><td colspan=1 rowspan=1 > Brad Turner </td><td colspan=1 rowspan=1 > Toni Graphia </td><td colspan=1 rowspan=1 > February 20, 2012 </td><td colspan=1 rowspan=1 > 2J6054 </td><td colspan=1 rowspan=1 > 5.98 </td></tr>
<tr> <td colspan=7 rowspan=1 > Johnny McKee, another former Alcatraz prisoner, returns and begins to poison the people of San Francisco, particularly men who behave similarly to grade-school bullies. </td></tr>
<tr> <th colspan=1 rowspan=1 > 8 </th><td colspan=1 rowspan=1 > "The Ames Brothers" </td><td colspan=1 rowspan=1 > Nick Copus </td><td colspan=1 rowspan=1 > Robert Hull </td><td colspan=1 rowspan=1 > March 5, 2012 </td><td colspan=1 rowspan=1 > 2J6059 </td><td colspan=1 rowspan=1 > 5.82 </td></tr>
<tr> <td colspan=7 rowspan=1 > When brothers Herman and Pinky Ames, who almost escaped in 1961, return to modern times, Soto gets caught and kidnapped by the ultra-violent duo as they follow a map in the hunt for a certain treasure, resulting in a tense confrontation in Alcatraz itself. </td></tr>
<tr> <th colspan=1 rowspan=1 > 9 </th><td colspan=1 rowspan=1 > "Sonny Burnett" </td><td colspan=1 rowspan=1 > Paul Edwards </td><td colspan=1 rowspan=1 > Teleplay by: Toni Graphia & Robert Hull Story by: Toni Graphia </td><td colspan=1 rowspan=1 > March 5, 2012 </td><td colspan=1 rowspan=1 > 2J6060 </td><td colspan=1 rowspan=1 > 5.47 </td></tr>
<tr> <td colspan=7 rowspan=1 > Sonny Burnett, sent to 1960 Alcatraz for kidnapping wealthy people and holding them for outrageous ransoms, appears in the present, seeking revenge from Warden Tiller's treatment of him in the past. </td></tr>
<tr> <th colspan=1 rowspan=1 > 10 </th><td colspan=1 rowspan=1 > "Clarence Montgomery" </td><td colspan=1 rowspan=1 > Jack Bender </td><td colspan=1 rowspan=1 > Leigh Dana Jackson </td><td colspan=1 rowspan=1 > March 12, 2012 </td><td colspan=1 rowspan=1 > 2J6057 </td><td colspan=1 rowspan=1 > 5.07 </td></tr>
<tr> <td colspan=7 rowspan=1 > After a woman is found dead on a golf course, killed in a similar manner to the murdered girlfriend of former Alcatraz inmate Clarence Montgomery, the team begins to suspect that the innocent Montgomery, who was falsely accused of and imprisoned for murdering his girlfriend, has returned, and is now committing crimes similar to that which he was imprisoned for. </td></tr>
<tr> <th colspan=1 rowspan=1 > 11 </th><td colspan=1 rowspan=1 > "Webb Porter" </td><td colspan=1 rowspan=1 > Jack Bender </td><td colspan=1 rowspan=1 > Steven Lilien & Bryan Wynbrandt </td><td colspan=1 rowspan=1 > March 19, 2012 </td><td colspan=1 rowspan=1 > 2J6061 </td><td colspan=1 rowspan=1 > 5.04 </td></tr>
<tr> <td colspan=7 rowspan=1 > Sent to Alcatraz for killing his mother, who tried to drown him when he was younger, violin-playing former inmate Webb Porter resurfaces. </td></tr>
<tr> <th colspan=1 rowspan=1 > 12 </th><td colspan=1 rowspan=1 > "Garrett Stillman" </td><td colspan=1 rowspan=1 > Eagle Egilsson </td><td colspan=1 rowspan=1 > Leigh Dana Jackson & Coleman Herbert </td><td colspan=1 rowspan=1 > March 26, 2012 </td><td colspan=1 rowspan=1 > 2J6062 </td><td colspan=1 rowspan=1 > 4.78 </td></tr>
<tr> <td colspan=7 rowspan=1 > Doc and Rebecca close in on a man who may be the key to revealing the secrets behind all the returning criminals. </td></tr>
<tr> <th class="highlighted"  colspan=1 rowspan=1 > 13 </th><td colspan=1 rowspan=1 > "Tommy Madsen" </td><td colspan=1 rowspan=1 > Aaron Lipstadt </td><td colspan=1 rowspan=1 > Daniel Pyne & Jennifer Johnson </td><td colspan=1 rowspan=1 > March 26, 2012 </td><td colspan=1 rowspan=1 > 2J6063 </td><td class="highlighted"  colspan=1 rowspan=1 > 4.75 </td></tr>
<tr> <td colspan=7 rowspan=1 > Rebecca finds the man who killed her partner. The episode includes a recreation of the chase scene in Bullitt. </td></tr>
</table>
Question:
How does the viewership compare for Alcatraz's pilot and final episodes?
Answer:
The Alcatraz series opened with over 10 million U.S. viewers, but for the season finale, it had decreased to 4.75 million U.S viewers, the series' lowest viewership.