ARL statistics and the increase in holdings

OCLC research and ARL have published some interesting data in Changing Global Book Collection Patterns in ARL Libraries. The thrust of the paper is about the pattern of holdings of foreign publications. However, what I grabbed onto in the first few pages were the figures on titles and holdings in general. Figure 1 on page 2 shows the number of records in OCLC for all books published before 1980 and after 1980:

Pre-1980: 15,222,793
1980-2004: 13,210,095

Basically, the number of titles for all books before 1980 is only barely greater than the number of titles in the 24 years since 1980.

Figure 4 shows numbers of holdings in the entire OCLC catalog:

Pre-1980: 330,291,378
1980-2004: 388,721,240

ARL libraries aren't as top-heavy in the 1980-2004 level as are other OCLC libraries, which makes sense. But what this does tell me is that libraries are facing a huge increase in volumes that they must manage, and it must be because there is a lot more being published. Wikipedia reports these figures for the number of titles published per year in the UK and US. Presumably this is book titles only:

1. United Kingdom (1996) 107,263 ^[2] (2005) 206,000, ^[3]
2. United States (1996) 68,175 ^[5] (2005) 172,000, ^[3]

Note the near doubling in the UK, and near trebling in the US. This may not be news, but I have never before seen figures that confirmed my general feeling that it's all speeding up.