Humble request of older drivers

Statistics are overall an interesting field of study, and I sincerely wish I had gone beyond my Minor in Stats.

The NHTSA link takes awhile to get to the point, and I do have some issue with their selection of "statistics." Overall, I'm quite turned off when a "total number" involvement is brought up without mention of the population size and/or sample size.

That is, has the TOTAL NUMBER of drivers in the 16-20 cohort or the 21-24 cohort increased, decreased, or remained the same over a representative time period? Eg: reference data to T=10y, T=20y, T=30y, etc.

Note: to group a sample into ages is known as a "cohort." The sample cohort range of 16-20, 21-24, and 25-54 is a typical cohort range.

If I can extrapolate for a moment, based on public domain data available at the U.S. Census Bureau (http://www.census.gov), let's examine the data:

For the 2000 Census, the total population 15-19 cohort is 20,219,890 persons. The 20-24 cohort is 18,964,001 persons. The 25-54 cohort (Blended) is 123,054,288 persons.

For the 1990 Census, the total population 15-19 cohort is 17,754015 persons. The 20-24 cohort is 19, 020,312 persons. The 25-54 cohort (Blended) is 105,977,921 persons.

It would take some time to further extrapolate based on percentage of drivers to each cohort, especially the "blended" cohort of 25-54 that severely distorts the cohort ranking towards that cohort.

However, based on the NHTSA link Figure 7 (Fatal involvement where drinking is a factor, per cap of 100,000 persons), the 21-24 cohort has the highest involvement, followed by the 16-20 cohort, then the 25-54 cohort.

What Figure 7 and especially Figure 8 appears to represent is the fact that increased law enforcement activity has dramatically reduced the fatal involvement where drinking is a factor.

I prefer the linked algorithm model used in:

http://www.nhtsa.dot.gov/people/injury/res...elderlydrv.html

http://www.nhtsa.dot.gov/people/injury/res...pt/summary.html

http://www.nhtsa.dot.gov/people/injury/res...t/appendix.html

http://www.nhtsa.dot.gov/people/injury/res...Alongreport.pdf

The following still illustrates that drivers under 24 are - by far - the most dangerous on the road:

http://www-nrd.nhtsa.dot.gov/pdf/nrd-30/NC...98/AgeSex96.pdf

In particular, the following summarizes why elderly drivers over 60 are more likely to expire or suffer serious injury in a crash:

http://www-nrd.nhtsa.dot.gov/departments/n...um_fragile.html