2010 Census...
Clark County 2010......16,335    (-4.05% from 2000 Census)
Clark County 2000......17,008  
    Marshall went from 3,771 in 2000 to 3,933 in 2010 (+4.3%)
    Casey went from 2,942 in 2000 to 2,769 in 2010 (-5.9%)
    Martinsville went from 1,225 in 2000 to 1,167 in 2010  (-4.7%)

FYI
    Coles County...53,873 (+1.3%)
   Crawford County...19,817 (-3.1%)
   Edgar County...18,576 (-5.7)
   Cook County (Chicago)...182,066 (-3.4%)