1 INTRODUCTION  
2 METHODS  
2.1 Estimating DLAs in a Column Density Bin  
3 RESULTS  
3.1 Column Density Distribution Function  
3.2 Redshift Evolution of DLAs  
4 CHECKS FOR SYSTEMATICS  
4.1 Effect of SNR  
4.2 Quasar Redshift  
5 CONCLUSION