“The steep rise in bond yields since September [and the robust equity markets despite Brexit] had a remarkably positive impact on pension solvency"

I do not get this...the bond part I mean...they hold a variety of bonds...a variety of terms...they are not trading them...just collecting the coupon...I would think.
Rates went up...value of bonds declined.
Are they saying that "because we have an extra .7% yield we do not need as much contributions per year to achieve our projected future "payout rate" ?
Or are they holding a lot of corporate bonds that went up in value a bit ??
Maybe it has to do with the definition of "solvency" is for a pension fund....
Did they sell some equities and buy into these (higher) bond yields ?

Or what

a confused reader