Maintaining Calc spreadsheet w/ multiple headers/subheaders

> Hello,
>
> Here is a scenario that I am trying to deal with in a Calc spreadsheet:
>
> (1) Every year Bill and Nancy measure the weights and heights of four
> people.
>
> (2) The four people being measured are Fred, Joe, Alice, and Beatrice.
>
> Right now the measurements for two years, 2008 and 2009, have been entered
> into this spreadsheet:
>
> screenshot (https://imgur.com/xCy0y)
>

> Hello,
>
> Here is a scenario that I am trying to deal with in a Calc spreadsheet:
>
> (1) Every year Bill and Nancy measure the weights and heights of four
> people.
>
> (2) The four people being measured are Fred, Joe, Alice, and Beatrice.
>
> Right now the measurements for two years, 2008 and 2009, have been entered
> into this spreadsheet:
>
> screenshot (https://imgur.com/xCy0y)
>
> ODS file (https://min.us/muyVAlDHC)
>
> As you can see, right now this information is organised in the spreadsheet
> by multiple subheadings. The problem is that I am having a hard time getting
> Calc to filter and sort this information. For example, I don't know how to
> ask Calc to sort the rows by the height measured by Bill in 2009. The sort
> function in the data menu seems to expect that there is only one heading,
> and not multiple "layers" of headings arranged in rows.
>
> Another issue is that this spreadsheet might become unwieldy when more
> measurers (in addition to Bill and Nancy) start in, say, 2012, or when more
> subjects are added after the first four.
>
> I realise Calc can maintain multiple sheets in a file, and it also has some
> basic database capabilities. Can anyone provide recommendations on how to
> enhance my current sheet so that it is scalable and more easilty queried?