Madras and Bombay presidencies totalled 635 instances of sati over the same ten-year period. The 1829 missionary report does not provide its sources and acknowledges that "no correct idea can be formed of the number of murders occasioned by suttees", then states some of the statistics is based on "conjectures". According to Yang, these "numbers are fraught with problems". William Bentinck, in an 1829 report, stated without specifying the year or period, that "of the 463 satis occurring in the whole of the Presidency of Fort William, 420 took place in Bengal, Behar, and Orissa, or what is termed the Lower Provinces, and of these latter 287 in the Calcutta Division alone". For the Upper Provinces, Bentinck added, "in these Provinces the satis amount to forty three only upon a population of nearly twenty millions", i.e., average one sati per 465,000. Social composition and age distribution Anand Yang, speaking of the early nineteenth century, says that contrary to conventional wisdom, sati was not, in general, confined to being an upper class phenomenon, but spread through the classes/castes. In the 575 reported cases from 1823, for example, 41 percent were Brahmins, some 6 percent were Kshatriyas, whereas 2 percent were Vaishiyas, and 51 percent Sudras. In Banaras, though, in the 1815–1828 British records, the upper castes were only for two years represented with less than 70% of the total; in 1821, all sati were from the upper castes there. Yang notes that many studies seem to emphasise the young age of the widows who committed sati. However, by study of the British figures from 1815 to 1828, Yang states the overwhelming majority were ageing women: The statistics from 1825 to 1826 about two thirds were above the age of 40 when committing sati. Regional variations of incidence Anand Yang summarizes the regional variation in incidence of sati as follows: Konkan/Maharashtra Narayan H. Kulkarnee believes that sati came to be practised in medieval Maharashtra initially by the Maratha nobility claiming Rajput descent. Then, according to Kulkarnee, the practice of sati may have increased across caste distinctions as an honour-saving custom in the face of Muslim advances into the territory. But the practice never gained the prevalence seen in Rajasthan or Bengal, and social customs of actively dissuading a widow from committing sati are well established. Apparently not a single instance of forced sati is attested for the 17th and 18th centuries CE.