Problem centring table entry

I am creating a table.  One column is quite narrow (15mm),  contains a
Paragraph() entry because I need wordwrap in some cases.  The table cell
is centred as is the Paragraph().

As you can see on the attached picture,  most of the time the cells
contain only a number and these centre fine.  Some cells contain words
and a number, separated by "<br /><br />".  Where the words are short
the contents are still centred - as in the "Stacey House" row.

However,  if the cell contains longer words the whole contents move left
and sometimes go outside the cell when otherwise they would have fitted
- see the top two rows.

Is there anyway to stop this and keep the cell centred?

I am using Reportlab 3.1.8 with Python 3.4 on Debian.

Regards

Tony Middleton