Which preposition to use with stringency

of Occurrences 11%

Then the stringency of the money market equalled the previous inflation.

in Occurrences 4%

In 1819 an event occurred, of no great importance in itself, but which was made the excuse for increased stringency in the suppression of liberal sentiments throughout Germany.

to Occurrences 2%

The efflux of silver brought general impoverishment to China, widespread financial stringency to the state, and continuous financial crises and inflation.

Which preposition to use with  stringency