Year Number 1981 1 1983 1 1984 2 1985 297 1988 889 1990 1324 1991 1491 1992 1560 1994 5360 1995 5290 1999 4684 2001 4370 2002 4046 2005 1859 2007 1752 2008 1684 2014 1450 2015 1473 2016 1078 2017 1327 2018 716 2019 872 2020 809 2021 667