how many hands should you be winning at showdown

[alexd231232]

playing mostly sit and go's with these statistics so i figured i'd post in this forum.
Hold'em (Real Money):

2000 hands played and saw flop:
- 338 times out of 478 while in small blind (70%)
- 346 times out of 475 while in big blind (72%)
- 471 times out of 1047 in other positions (44%)
- a total of 1155 times out of 2000 (57%)

Pots won at showdown - 180 out of 328 (54%)
Pots won without showdown - 232

those numbers look okay, should you be winning more than 50 percent of the time at showdown?
How many, out of 2000, should you be winning without?