evidence: With regard to fertility rates, the study found that Muslims, who had the highest fertility rate, also had the sharpest decline in fertility rates. From 1992 to 2015, the total fertility rates of Muslims declined from 4.4 to 2.6, while that of Hindus declined from 3.3 to 2.1, indicating that "the gaps in childbearing between India’s religious groups are much smaller than they used to be." The average fertility rate in India today is 2.2, which is higher than the rates in economically advanced countries such as the U.S. (1.6), but much lower than what it was in 1992 (3.4) or 1951 (5.9). [...] Cautioning that religion is by no means the only or even the primary factor affecting fertility rates, the study noted that women in central India tended to have more children, with Bihar and Uttar Pradesh showing a total fertility rate (TFR) of 3.4 and 2.7 respectively, in contrast to a TFR of 1.7 and 1.6 in Tamil Nadu and Kerala respectively.