How long does it take SEGA to normally announce localization of a Yakuza game?

Did some research as I was curious myself on the usual announcement cycle of the series.

Here’s how it breaks down:

Yakuza 1
December 8, 2005 – Released in JP
February 23, 2006 – Announced for NA
Time: 77 Days

Yakuza 2
December 7, 2006 – Released in JP
July 16, 2008 – Announced for NA
Time: 587 Days

Kenzan
March 6, 2008 – Released in JP
Never – Announced for NA
Time: NA

Yakuza 3
February 26, 2009 – Released in JP
Dec 08, 2009 – Announced for NA
Time: 285 Days

Yakuza 4
March 18, 2010 – Released in JP
Jun 08, 2010 – Announced for NA
Time: 82 Days

Kurohyou
September 22, 2010 – Released in JP
Never – Announced for NA
Time: NA

Dead Souls
June 9, 2011 – Released in JP
October 5, 2011 – Announced for NA
Time: 118 Days

Kurohyou 2
March 22 2012 – Released in JP
Never – Announced for NA
Time: NA

Yakuza 5
December 6, 2012 – Released in JP
December 6, 2014 – Announced for NA
Time: 731 Days

Ishin
February 22, 2014 – Released in JP
Never – Announced for NA
Time: 145 Days (So far as of July/16/2014)