So, to put it in very quick mathematical perspective -
Between June 1943 and May 1945 (the part NOT included in SHV), what we have is
17.2% of total U-boat successes and
67.1% of U-boat losses.
If we do a quick-and-dirty correlation of this to the total lives lost in the Battle of the Atlantic as a whole, you are looking at around 5,200 merchant marine seamen, and 18,800 U-boat men who lost their lives during this time.
(*on the other hand, here's another sobering statistic for you - the total number of deaths on both sides in this tragic period of the Atlantic battle is less than 1/3 the number of people instantly killed by the bomb at Hiroshima, and about 1.7% of the total number of people killed at Auschwitz (i.e. 58 times less). Talk about perspective...)