Complex sentence: For the entire Malayan Campaign, but largely on 12,13 and 14 February 1942 in Singapore, the Malay Regiment suffered a total of 159 killed (six British officers, seven Malay officers, and 146 other ranks) and a large but unspecified number wounded.
Split into simpler sentences: For the entire Malayan Campaign, but largely on 12,13 and 14 February 1942 in Singapore, the Malay Regiment suffered a total of 159 killed. Six of them were British officers, seven Malay officers, 146 other ranks and a large but unspecified number wounded.