1) 58.2 TFlop is pathetically weak for a super computer.  A 5970 graphics card has about 4.6 TFLOPs.  So it is roughly equal to the floating point math calculations of ~12 5970 GPUs (4x that if it is double precision).

2) Super computers aren't optimized for Bitcoin mining.  They have lots of very expensive parts.  Terrabytes of ram, petabytes of storage, redundant backups, high speed interconnects.  All that adds up to hundreds of millions of dollars and produces 0.0 hashes.

3) The largest super computers in the world is 11,280 TFLOPs.  http://i.top500.org/system/177232

4) That ratio is just a guestimate.  Bitcoin mining uses integer math TFLOPS are a measure of floating point math.  Saying the network is 137.91 PFLOPS isn't exactly accurate.  It is 0 PFLOPS however it likely has the computing hardware that combined is roughly equal to ~100 PFLOPS.