Actually, Jason, there were 8 years between the release of the Birds $20 and the release of the Journey $10 (approximately 7 1/2 years to be exact!). Even though the birds $20 was dated 1991, it was officially released in June of 1993, but the Journey $10 was dated "Issue of 2001" and was released in January 2001.
Here are some time periods from the release of the Birds Issue to the Journey series:
$5 Birds: 1986 $5 Journey: 2002 (16 years)
$10 Birds: 1989 $10 Journey: 2001 (12 years)
$20 Birds: 1993 $20 Journey: 2004?? (11 years??)
$50 Birds: 1989 $50 Journey: 2004?? (15 years??)
$100 Birds: 1990 $100 Journey: 2004 (14 years)
According to my theories, the denomination with the longest timespace between the birds and Journey issues is the $5 note with 16 years.
The amount of timespace between the release of the Birds $2 note (1986) and the so-called "twoonie" coin (1996) is a little bit less than ten years since the 1986 $2 note was issued in the fall of 1986 and the $2 coin was launched in February of 1996. That's about 9 years and so many months between the birds $2 and the $2 coin.
And that is my twoonie's worth.
Later, Jonathan