In the 1840s Nicholas I of Russia reduced 64,000 szlachta to commoner status. Despite this, 62.8% of Russias nobles were szlachta in 1858 and still 46.1% in 1897. Serfdom was abolished in Russian Poland on February 19, 1864. It was deliberately enacted in a way that would ruin the szlachta. It was the only area where peasants paid the market price in redemption for the land (the average for the empire was 34% above the market price). All land taken from Polish peasants since 1846 was to be returned without redemption payments. The ex-serfs could only sell land to other peasants, not szlachta. 90% of the ex-serfs in the empire who actually gained land after 1861 were in the 8 western provinces. Along with Romania, Polish landless or domestic serfs were the only ones to be given land after serfdom was abolished. All this was to punish the szlachtas role in the uprisings of 1830 and 1863. By 1864 80% of szlachta were déclassé (downward social mobility),  petty nobles were worse off than the average serf, 48.9% of land in Russian Poland was in peasant hands, nobles still held 46%. In the Second Polish Republic the privileges of the nobility were lawfully abolished by the March Constitution (Poland) in 1921 and as such not granted by any future Poland law.
Question: By how many percent did szlachtas decrease from 1858 to 1897?
Answer: 16.7