need some help to provide eveidence of my loss

Hello all, First of all thanks to any one who help me regarding my issue. I did some trading in the year 2009-2010 and 2010-2011. Now I had a big loss in the year 2010-2011. I have made claim against my losses when logged the tax return for 2010-2011. Now I need to provide some eveidence to ato about my losses. I do not know how can I provide that evidence to ato. As I did a number of transaction in the year therefore I am not sure if there is one paper that I can get from
commsec stating that I had loss this much. Please help on this.