Year Number 1988 6619400 1989 6875100 1990 7207400 1991 7426600 1992 7683100 1993 8215000 1994 9417300 1995 9985700 1996 10701700 1997 10884300 1998 11586400 1999 12797200 2000 13384562 2001 12936051 2010 20932847.35207754 2011 20587558.889797587 2012 20924089.307821922 2013 19181953.6 2014 21690361.952764966 2017 26423477 2018 29543913.884630393 2019 26839242.579338048 2020 7717842.031 2021 7031655.584000001