months vs threats
threats
  60 ++------------+-------------+--------------+-------------+------------++
     +             +             +              +   "data/mt.sorted"   A    +
     |                                                                      |
  50 ++               A                                                    ++
     |                                     A                                |
     |                   A           A                                      |
  40 ++               AA                                                   ++
     |          AA    A  A                                                  |
     |  A         A    A                                                    |
  30 ++         A A A  A     AAA            A           A                  ++
     |       A AA    A AAA AAA        A                                     |
     |   A  A  AAAAAAAAAA  A A    A                     A                   |
  20 ++   A AAAAAAAAAAAA   AAAAAAA A  A    A                               ++
     |     AAAAAAAAAAAAAAAAA  AAA   AA A      A             AA             A|
     |  AAAAAAAAAAAAAAAAAAAAAA AAAA  AAAA A     A A                         |
  10 ++A AAAAAAAAAAAAAAAAAAAAAAAAAAAAA A  A   A                            ++
     | AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AA   A  A A A A             A   |
     + AAAAAAAAAAAAAAAAAAAAAAAAA AAAAA  AA     AA     A       +             +
   0 ++--AAAAAAAAAAAAAAAAAAAAAA-A+AA-AA---AA-A--+-------------+------------++
     0             50           100            150           200           250
                                     months