It's an interesting trend to see that dating back to the 600s or so NE we rarely see more than 1 or 2 women raised to the Shawl in any given year. In a few years we see as many as 3 women raised to Aes Sedai, but there are also stretches of as much as 5 years without a single woman raised.

Part of this is likely just due to only having about 1/5 of the total data, but there is also such a clear trend of numbers of women being raised since 978 and the generally shorter training time of these women.

Prior to 900 NE Training time averaged roughly 16 years, since 901 NE training time for the Tower dropped down to an average of 14 years. We also see at least 3 years in a row with 4+ Sisters raised to the Shawl, from what we have available that is unprecedented as it was rare to have more than 2 in a single year prior to this:

978 = 4 Raised (and at least one failure, RIP Ellid)
979 = 6 Raised
980 = 5 Raised
981 = 1 Raised
982 = 2 Raised

By 989 every woman we know of that was already in the Tower before or during the Vileness had been raised to the Shawl and training times had once again increased to an average of 16 years.

Seems clear that the Tower made some pretty strong moves to keep numbers of Aes Sedai up when we see so many senior sisters dying during the Vileness.

at least 16 senior Aes Sedai deaths during or right after the Vileness:

Gitara
Tamra
Meilyn
Kerene
Aisha
Citalia
Larelle
Valera
Marya
Ludice

Jarna
Merean
at least 2 unnamed Black Ajah Supreme Council members

Seirin Vayu
Marith Jaen

Seems a bit of balance was being secured by raising 15 women in 3 years and additional 3 over the next couple of years, for a total of 18 new Aes Sedai raised between 978-982 (for these 18 the average training time was an even shorter 13 years). These 18 women were mostly quite strong for Aes Sedai too, with only 3 being below the level 19 threshold for Traveling.