This site shows daily changes in the tanker index, but doesn't provide dollar rate or historic data. I just tried a quick search and couldn't find one that did.

http://www.lloydslist.com/

The comment that tanker rates are set to plunge seems accurate (see below), but doesn't provide any insight into oil depletion. We already know that exports haven't increased, so one would expect tanker rates to drop, regardless of whether the cause was limited supply or reduced demand.

Tanker Rates May Drop for Third Year, Hurting Frontline, OSG
2007-01-05 05:16 (New York)

By Alaric Nightingale
Jan. 5 (Bloomberg) -- The cost of transporting oil on
supertankers may fall for a third consecutive year as crude
shipments ease and new vessels are launched, prompting owners to
sell ships as scrap metal or adapt them for other uses.
Companies including Frontline Ltd. and Overseas Shipholding
Group Inc. may earn about $43,000 a day for hauling 2-million-
barrel cargoes on the benchmark 40-day round trip between the
Middle East and Japan during 2007, according to the median
estimate of 10 analysts surveyed by Bloomberg. Earnings averaged
$59,250 a day last year.
``We are looking at a year of high vessel deliveries and
softer trading conditions than typically prevailed over the past
three years,'' said Mark Jenkins, a senior analyst in London for
Simpson, Spence & Young Ltd., the world's largest closely held
shipbroker. ``That's likely to result in some owners of older
ships finally accepting that it's time to cash in their chips.''
Earnings for Hamilton, Bermuda-based Frontline, whose fleet
has the world's biggest carrying capacity, and Overseas
Shipholding are being squeezed by an expansion in the global
tanker fleet and a drop in Middle East exports. Since November,
OPEC has pledged to cut crude supplies by 1.7 million barrels a
day. Next year, 35 supertankers enter service, more than double
this year's additions.

$40,000 a Day

Owners probably will earn $40,000 a day from their
supertankers in the first quarter on the Middle East-Asia
voyage, according to the median estimate of nine of the
analysts. That compares with $71,910 last year, according to
London-based shipbroker Galbraith's Ltd.
The very large crude carriers, or VLCCs, that will either
head for conversion yards or be broken up for scrap are likely
to be those with one layer of steel separating their cargo tanks
from the ocean. Single-hull vessels, due to be banned by the
United Nations from 2010, usually earn less and are a higher
risk to the environment than those with two hulls.
Frontline's profit fell 19 percent to $381 million in the
nine months to September as a glut of vessels reduced hire
rates. Earnings at New York-based Overseas Shipholding, the
biggest U.S.-based tanker owner, dropped almost 21 percent to
$279.4 million. Frontline said fourth-quarter performance would
be even ``weaker'' as reduced OPEC shipments cut vessel demand.
Hire rates for VLCCs dipped below Frontline's stated break-
even levels at one stage in the fourth quarter. Profit from the
company's single-hull tankers probably was hit even harder,
earning about $10,000 a day less than double hulls, Chief
Executive Officer Bjorn Sjaastad said in November.
Just as earnings for the vessels declines, a rally in crude
prices is presenting owners with other, more profitable ways of
employing them.

Baltic Dry is the standard. Perhaps u can get a friendly tanker link from one of the sites that cover it.

http://www.slate.com/id/2090303/
http://investmenttools.com/futures/bdi_baltic_dry_index.htm

In the meantime, here's a historic view compliments of iea:

http://trendlines.ca/energy.htm#misc