HWA - Mercedes had begun to gain the upper hand in 2004 ( with 13 wins from 20 races ) .
HWA - Mercedes increased its development effort to win 18 races in 2005 .
HWA - Mercedes had begun to gain the upper hand in 2004 ( with 13 wins from 20 races ) , and increased its development effort to win 18 races in 2005 .