| Year | W (billion $) | P | K | Q1 | Q2 |
| 1990 | 11.9 | 2/15 | 4.13 | 4.42 | 0.03 |
| 1991 | 11.9 | 2/15 | 3.89 | 0.54 | 0.03 |
| 1992 | 11.9 | 2/15 | 3.33 | 0.29 | 0.03 |
| 1993 | 11.9 | 2/15 | 2.70 | 0.16 | 0.03 |
| 1994 | 11.9 | 2/15 | 2.83 | 0.36 | 0.03 |
| 1995 | 11.9 | 2/15 | 3.06 | 0.68 | 0.03 |
| 1996 | 11.9 | 2/15 | 3.13 | 0.73 | 0.03 |
| 1997 | 11.9 | 2/15 | 3.20 | 1.17 | 0.03 |
| 1998 | 11.9 | 2/15 | 3.00 | 0.55 | 0.02 |
| 1999 | 11.9 | 2/15 | 3.03 | 1.53 | 0.02 |
| 2000 | 11.9 | 2/15 | 3.05 | 1.26 | 0.04 |
| 2001 | 11.9 | 2/15 | 2.98 | 0.88 | 0.03 |
| 2002 | 11.9 | 2/15 | 2.80 | 0.65 | 0.03 |
| 2003 | 11.9 | 2/15 | 2.47 | 0.50 | 0.04 |
| 2004 | 11.9 | 2/15 | 2.30 | 0.65 | 0.06 |
| 2005 | 11.9 | 2/15 | 2.11 | 0.66 | 0.07 |
| 2006 | 11.9 | 2/15 | 1.99 | 0.70 | 0.07 |
| 2007 | 11.9 | 2/15 | 1.97 | 0.68 | 0.07 |
| 2008 | 11.9 | 2/15 | 1.85 | 0.71 | 0.08 |
| 2009 | 11.9 | 2/15 | 1.55 | 0.38 | 0.06 |
| 2010 | 11.9 | 2/15 | 1.64 | 1.08 | 0.07 |
| 2011 | 11.9 | 2/15 | 1.57 | 0.65 | 0.08 |
| 2012 | 11.9 | 2/15 | 1.44 | 0.63 | 0.08 |
| 2013 | 11.9 | 2/15 | 1.33 | 0.57 | 0.07 |
| 2014 | 11.9 | 2/15 | 1.26 | 0.60 | 0.06 |
| 2015 | 11.9 | 2/15 | 1.20 | 0.59 | 0.04 |
| 2016 | 11.9 | 2/15 | 1.25 | 0.92 | 0.04 |