To whom can help,

I work for the NYS Department of Environmental Conservation in the department of lands and forests. I have a question concerning the total percent of forested land in New York State befoe the 1900's.

Here is what I have so far:

Forest land cover figures-- forest land is defined as land with at least 10% stocking of trees of any size, or that formerly had such tree cover and is not currently developed for a non-forest use.

Total land area of New York State-- 30.2 million acres

1900-- 7 million acres--appox. 23%
1925-- 9 million acres--approx. 30%
1953--15.1 million acres-- approx. 50%
1968-- 17.3 million acres-- approx. 57%
1980--18.5 million acres--approx. 61%
1993-- 18.6 million acres-- approx. 62%

As early as we can go will be greatly appreciated.
Thank you very much for who ever can assist me.