Gold and silver etf prices compared to bullion spot

I thought it would be good to keep an historical record of the ratio of etf prices compared to bullion. The intention is to detect early warning signs of etf's falling behind the spot price as market opinion starts believing that certain etf's are not going to deliver.

Or perhaps COMEX price falling behind because the market no longer believes it will deliver.

I don't think there is enough stress in the market to really need this yet ( 7/04/10 ) but I'll start the thread anyway.

I think this is a useful reference as a starting point as it has toz, kilos, and 7 different currencies all immediately accessible.
http://www.kitco.com/market/us_charts.html

So, one post ( page ) reserved for each different silver or gold etf that anyone wants to put on. Bear in mind that the comparison will only work when both prices are live and both markets is open. And of course both prices must be in the same currency. Also it's not the ratio between etf and spot that's important as this is all down to history of storage cost and other things. But if the ratio changes that is a measure of trust by the market in whether the etf is expected to deliver.