Original sentence: However, due to other voting mechanisms usually used in conjunction with STV, such as a district or constituency system, an election using STV may not guarantee proportionality (across all districts put together).STV provides proportionality by transferring votes to minimise their waste.The lack of proportionality is derived from unequal representation rather than any deficiency in STV
Edited sentence: Attention must be drawn to the fact that there have been allegations of gerrymandering during redistricting for this and other Maltese elections, and that just 2% separated the two leading parties (49% to 51%).However, due to other voting mechanisms usually used in conjunction with proportional systems, such as a district or constituency system, an election using any proportional system may not guarantee proportionality (across all districts put together).In Eire (Republic of Ireland) STV has produced an average deviation from proportionality of 3.4% since 1948 , as this is an average deviation over many elections, then deviations can be higher in specific elections, leading to non permanent deviations from proportionality during elections.It must be noted that first preferences do not represent the proporionality of the entire vote due to transfers of excess votes.Like all proportional systems, STV provides proportionality by transferring votes to minimise their waste.Popular candidates in unpopular parties may find that they fail to retain any excess votes for their party.The lack of proportionality is derived from unequal representation.The use of small constituencies all electing the same number of representatives may also have been responsible for deviations from proportionality in Maltese elections