As women have gained status in the job market and increased their incomes, the birth of a child has come to represent a proportionally larger loss of income.
1960 48 253 333 255 169 79 13 - 1965 36 261 326 195 100 41 6 - 1970 40 238 293 147 59 20 3 - 1975 34 191 212 80 26 8 2 22.9