solemn vs unworried

solemn

adj
  • Characterized by or performed with appropriate or great ceremony or formality. 

  • Of or pertaining to religious ceremonies and rites; (generally) religious in nature; sacred. 

  • Inspiring serious feelings or thoughts; sombrely impressive. 

  • Deeply serious and sombre; grave. 

unworried

adj
  • Free of worries. 

How often have the words solemn and unworried occurred in a corpus of books? (source: Google Ngram Viewer )