I need to find Lusche's chart...as of today, of 2147 kills by lancasters, 811 were vehicles. I may be reading the stats wrong.
A huge percentage of the Lancaster's kills are GV, because the lanc has a hard time to shoot enemy fighters down.
But if you look at my recent stats (see link in my sig), you will see that only a surprisingly small fraction of tanks (0.6% in case of Panzer IV and M4(76) in 2010) are actually killed by Lancasters.