Aggressive discounting of fixed mortgage rates this year has caught the attention of borrowers, who increased their demand for fixed-rate loans in February.Mortgage aggregator AFG reported yesterday that 24.1 per cent of the mortgages its brokers wrote in February were fixed-rate mortgages.  The proportion of fixed-rate loans jumped from 16.3 per cent in January, and from 18.7 per cent in December. According to Infochoice, one-year fixed mortgage rates have fallen by an average of 17 basis points since the beginning of November. The three-year fixed rate has fallen by an average of 14 basis points over the same period and the five-year rate has fallen by an average of 14 bps.The average one-year rate is now 5.47 per cent, with the lowest rate in the market being 4.98 per cent.The average three-year rate is 5.48 per cent, with the lowest rate being 5.09 per cent. And the average five-year rate is 6.01 per cent, with the lowest rate being 5.69 per cent.The average standard variable rate for the lenders in Infochoice's database is 6.07 per cent. Rate City puts the average at 5.97 per cent.