Frequencies for ap variable in dapstate2014 dataset :

                              ap |      Freq.     Percent        Cum.
---------------------------------+-----------------------------------
                15.6428794073426 |          1        1.92        1.92
                16.0291507821267 |          1        1.92        3.85
                 17.035447248591 |          1        1.92        5.77
                17.3057999932064 |          1        1.92        7.69
                17.4325895908771 |          1        1.92        9.62
                17.5799082329043 |          1        1.92       11.54
                17.6318641847734 |          1        1.92       13.46
                17.6773711984247 |          1        1.92       15.38
                17.7399206188615 |          1        1.92       17.31
                17.7854943618523 |          1        1.92       19.23
                18.3099509965559 |          1        1.92       21.15
                18.7163874076702 |          1        1.92       23.08
                19.8477347201736 |          1        1.92       25.00
                20.0750104246306 |          1        1.92       26.92
                20.0960118004796 |          1        1.92       28.85
                20.2459380027992 |          1        1.92       30.77
                20.4316188731546 |          1        1.92       32.69
                21.3476559934463 |          1        1.92       34.62
                21.4329626918783 |          1        1.92       36.54
                22.2608932223698 |          1        1.92       38.46
                22.4354031113875 |          1        1.92       40.38
                22.5541113430154 |          1        1.92       42.31
                22.5631599070659 |          1        1.92       44.23
                23.1335654403233 |          1        1.92       46.15
                23.2132711393553 |          1        1.92       48.08
                23.2903007373585 |          1        1.92       50.00
                23.4993164124685 |          1        1.92       51.92
                23.5090643513247 |          1        1.92       53.85
                 23.750174597338 |          1        1.92       55.77
                24.1667279154109 |          1        1.92       57.69
                24.2824961041715 |          1        1.92       59.62
                24.3213811652589 |          1        1.92       61.54
                24.6600563184431 |          1        1.92       63.46
                24.6733925225821 |          1        1.92       65.38
                25.0986059205108 |          1        1.92       67.31
                26.3114089355973 |          1        1.92       69.23
                26.5526161608622 |          1        1.92       71.15
                26.8086570531494 |          1        1.92       73.08
                26.9093566532524 |          1        1.92       75.00
                27.0461659863046 |          1        1.92       76.92
                27.2637324287011 |          1        1.92       78.85
                27.8269091255444 |          1        1.92       80.77
                27.9089807804663 |          1        1.92       82.69
                29.1019889555014 |          1        1.92       84.62
                 29.108915205339 |          1        1.92       86.54
                30.3819783937606 |          1        1.92       88.46
                30.8160779147865 |          1        1.92       90.38
                32.1882049783187 |          1        1.92       92.31
                32.6354066118788 |          1        1.92       94.23
                34.1921808374702 |          1        1.92       96.15
                35.0957590849372 |          1        1.92       98.08
                37.3393982523977 |          1        1.92      100.00
---------------------------------+-----------------------------------
                           Total |         52      100.00

by Jean Roth , jroth@nber.org , 18 Oct 2016