Interesting, thanks for pointing out the update.
So it appears the amount in the "Current" column adds into the mysterious $21 million figure in the "Total" column.
Still confusing, but at least that 21 million number is growing. The positive side of me is saying, "Maybe that is a running total of what is being paid out so far, starting on 3/30, and that number will grow as more is received through 3/31/2017."
This might also explain why this award ID (HSTS0415JCT8502) has been changed a few times due to "modified delivery dates," (see modification P00003 just underneath), thanks to the protest.
Not saying this is right, but if so, the Q3 earnings report in mid-May will be great!