Drescher pressure
1993       -       -       -       -       -       -       -       -       -       -       -   981.5
1994   984.8       -       -       -       -       -       -       -       -       -       -   978.8
1995   984.1   979.2   980.8   984.3   979.3   985.5   992.7   982.3   979.6   983.0   979.4   977.4
1996   985.7   985.3   978.3   982.3   981.0   987.4   977.9   984.6   989.4   975.4   982.8   985.4
1997   987.9   987.7   975.4   985.8   978.3   988.2   980.1   980.5   978.0   981.6   987.0   988.9
1998   983.8   979.8   980.0   974.8   976.1   978.7   977.2   977.9   980.2   979.8   975.3   978.9
1999   984.6   984.1   984.1   976.6   980.8   993.4   981.6   974.6   979.7   969.8   979.9   974.1
2000   977.6   983.2   985.6   984.7   980.9   984.2   989.8   981.0   985.6   978.8   983.7   993.4
2001       -       -       -       -       -       -       -       -       -       -       -       -
2002       -       -       -       -       -       -       -       -       -       -       -       -
2003       -       -       -       -       -   991.5       -       -       -       -       -       -
2004       -       -       -       -       -       -       -       -       -       -       -       -
2005       -       -       -       -       -       -       -       -       -       -       -       -
2006       -       -       -       -       -       -       -       -       -       -       -       -
2007       -       -       -       -       -       -       -       -       -       -       -       -
2008       -       -       -       -       -       -       -       -       -       -       -       -
2009       -       -       -       -       -       -       -       -       -       -       -       -