Distribution of screen-time on Today

I'm just back from the PSA Media and Politics Group conference in Sunderland, where I presented a paper on the screen time given over to Italian politicians. Whilst there, I found out that Guy Starkey has compiled similar data [Powerpoint] on the screen-time given over to different parties on the BBC's Today programme during electoral periods. The trend revealed over the period 1997 - 2005 [not shown in the Powerpoint] was for the party in government to receive a greater share of interview time. There was, however, no indication whether this increase in time was associated with increased ferocity of interviewing technique, although the Powerpoint linked to suggests, if anything, the reverse for 1997, with Blair subject to particularly strong attacks.