Could you tell me when the AR regulator series was redesigned and released?

For the previous AR regulator with 4 digit code like AR4000, the sales of the regulator began in 1985 and the production was terminated in September 2005. 
The AR regulator with 2 digit code was released in November 2001 as a successor. Also, this product was renewed as a refreshed product with the combination of codes such as AR, 2 digits and the end code -A (e.g. AR40-∗∗-A). 
The refreshed product was released since April 2012.