Question on Sort node's actual rows

Greetings.

I'm looking at a plan: http://explain.depesz.com/s/sPv

And I have a question. Why in the following snippet `Sort` node
reports 128818 rows, although
child node returned only 352?

"-> Sort (cost=37.06..37.94 rows=352 width=20) (actual time=4.441..16.971
rows=128818 loops=1)
" Sort Key: ts.currency
" Sort Method: quicksort Memory: 52kB
" Buffers: shared hit=13
" -> Seq Scan on transaction_slip ts (cost=0.00..22.18 rows=352
width=20) (actual time=0.041..4.035 rows=352 loops=1)
" Filter: (account_id = 101)
" Rows Removed by Filter: 382
" Buffers: shared hit=13

This is:
PostgreSQL 9.3.1 on x86_64-apple-darwin12.5.0, compiled by
i686-apple-darwin11-llvm-gcc-4.2 (GCC) 4.2.1 (Based on Apple Inc. build
5658) (LLVM build 2336.11.00), 64-bit

--
Victor Y. Yegorov