Unknown_Attributes on SanDisk SSD U100 32GB

I am more interested in understanding how weared out is this device.
It's my work horse and I am taking it for a half-year odyssey
where replenishment is not handy. Thanks!

Ready to offer more information on request. Here is some to start with 
(with every value at 100 it look like either full fuel or peril to me).

$ sudo smartctl -A /dev/sda 
smartctl 6.2 2013-04-20 r3812 [x86_64-linux-3.11.0-14-generic] (local build)
Copyright (C) 2002-13, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF READ SMART DATA SECTION === 
SMART Attributes Data Structure revision number: 1 
Vendor Specific SMART Attributes with Thresholds: 
ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
   5 Reallocated_Sector_Ct   0x0002   100   100   000    Old_age   Always       -       0
   9 Power_On_Hours          0x0002   100   100   000    Old_age   Always       -       6568
  12 Power_Cycle_Count       0x0002   100   100   000    Old_age   Always       -       1555
171 Unknown_Attribute       0x0002   100   100   000    Old_age   Always       -       0
172 Unknown_Attribute       0x0002   100   100   000    Old_age   Always       -       0
173 Unknown_Attribute       0x0002   100   100   000    Old_age   Always       -       57
174 Unknown_Attribute       0x0002   100   100   000    Old_age   Always       -       296
187 Reported_Uncorrect      0x0002   100   100   000    Old_age   Always       -       0
230 Unknown_SSD_Attribute   0x0002   100   100   000    Old_age   Always       -       190
232 Available_Reservd_Space 0x0003   100   100   005    Pre-fail  Always       -       0
234 Unknown_Attribute       0x0002   100   100   000    Old_age   Always       -       350
241 Total_LBAs_Written      0x0002   100   100   000    Old_age   Always       -       742687258
242 Total_LBAs_Read         0x0002   100   100   000    Old_age   Always       -       1240775277

The device is:

# hdparm -i /dev/sda

/dev/sda:

  Model=SanDisk SSD U100 32GB, FwRev=10.02.00, SerialNo=120768303147
  Config={ Fixed }
  RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=0
  BuffType=unknown, BuffSize=unknown, MaxMultSect=1, MultSect=off
  CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=62533296
  IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
  PIO modes:  pio0 pio1 pio2 pio3 pio4
  DMA modes:  mdma0 mdma1 mdma2
  UDMA modes: udma0 udma1 udma2 udma3 udma4 udma5 *udma6
  AdvancedPM=no WriteCache=enabled
  Drive conforms to: unknown:  ATA/ATAPI-4,5,6,7

  * signifies the current active mode



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