| Year | 1981 | 1986 | 1991 | 1996 | 1997 | 1998 | 1999 | 2000 |
| No. | 632 | 998 | 1064 | 2163 | 1496 | 2418 | 2531 | 2803 |
| Year | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | 2007 | 2008 |
| No. | 1259 | 2281 | 3171 | 4360 | 6627 | 5272 | 4973 | 4120 |
| Year | 2009 | 2010 | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 |
| No. | 5711 | 5488 | 5171 | 5150 | 6680 | 6082 | 6090 | 5830 |
| Year | 2017 | 2018 | ||||||
| No. | 6788 | 9768 |
Footnote
All figures are collected from Intellectual Property Department since 1999.
