2012 Volume – Top 35 CBOE Options (SPX, VIX, GLD, EEM, et al.) and Investor Sentiment

I recently received a call regarding CBOE options to gain global exposure, and we discussed CBOE options on EEM, FXI, EWZ, EFA, and FXI.
The top 5 options in terms of total yearly volume at CBOE in 2012 were —
(both of the lists below are for index and ETF options, and the lists do not include options on single stocks such as AAPL).
174,457,138 SPX S&P 500® Index
132,658,552 SPY SPDR S&P 500 ETF Trust
110,739,796 VIX® CBOE Volatility Index®
25,510,746 QQQ PowerShares QQQ Trust
24,282,713 IWM iShares Trust – Russell 2000 Index Fund
The table below presents more stats (e.g., put and call volume and put/call ratios) for the top 35 options in terms of total yearly volume at CBOE in 2012. 
The put/call ratio numbers in the table below are particularly interesting to me. Changes in put/call ratios could be indicators of changes in investor sentiment.  Many of the big stock index options contacts (SPX, NDX, RUT and OEX) all have put/call ratios of 1.3 or higher. While there are buys and sellers for any options transaction, the higher put/call ratios for index options could be indicative of high use of protective puts on these options. On the other hand, the put/call ratios for the VIX, SLV, SDS, TBT, TZA, FAZ, and XLK options all are 0.6 or lower. To add protection for their portfolios, some investors consider the purchase of SPX put options and VIX call options. More information on CBOE put/call ratios is at — https://www.cboe.com/data/PutCallRatio.aspx