[R] How to find b entries using xPath?

[guox at ucalgary.ca]

We got all rows by:

library(XML)
doc =
htmlParse('http://www.statcan.gc.ca/daily-quotidien/090520/t090520b1-eng.htm')
rows = xpathSApply(doc, '//table/tbody/tr')

The last row is:

row_last = rows[15]
row_last

[[1]]
<tr><td id="t1stub17" class="stub1 RGBShade"><b>Unsmoothed composite
leading indicator</b></td>
<td align="right" headers="hdt1r1c2 t1stub17"
class="data"><b>221.8</b></td>
<td align="right" headers="hdt1r1c3 t1stub17"
class="data"><b>218.4</b></td>
<td align="right" headers="hdt1r1c4 t1stub17"
class="data"><b>217.1</b></td>
<td align="right" headers="hdt1r1c5 t1stub17"
class="data"><b>211.2</b></td>
<td align="right" headers="hdt1r1c6 t1stub17"
class="data"><b>209.4</b></td>
<td align="right" headers="hdt1r1c7 t1stub17"
class="data"><b>210.5</b></td>
<td align="right" headers="hdt1r1c8 t1stub17"
class="data"><b>0.5</b></td>
</tr>

How to find these b entries: Unsmoothed composite leading indicator,
221.8, 218.4, 217.1, 211.2, 209.4, 210.5, 0.5?
Thanks,

-james