This template computes the number (between 0 and 99), in its astronomical century, of the year in parameter.
{{YEARYY|
year}}
{{YEARYY|1900}}
returns 0{{YEARYY|1901}}
returns 1{{YEARYY|1909}}
returns 9{{YEARYY|1910}}
returns 10{{YEARYY|1999}}
returns 99{{YEARYY|2000}}
returns 0{{YEARYY|2001}}
returns 1{{YEARYY|2009}}
returns 9{{YEARYY|2010}}
returns 10{{YEARYY|2099}}
returns 99